Category Archives: Step by Step Instructions

Detailed instructions that teach how to make mosaic artwork.

How To Make Mosaic Patterns Without Drawing

You can and should spend more time “drawing” with tile than drawing with a pencil when most of the details in the mosaic are about the size the smallest piece of tile that can be cut.

If the smallest details of your design are larger than multiple tiles, then you should draw a detailed pattern, but most mosaic plaques are small enough so that nearly all lines are affected by limitations in how small the tile can be cut, and drawing patterns for these can be counterproductive and cloud judgment.

Improvise Loosely On A Photo Or Image Used As A “Pattern”

HERE’S WHY NOT TO DRAW FOR SMALLS: Every element in your drawing will need to be a multiple of tiles wide or a fraction wide. Until you understand those multiples and fractions in practical terms of what you can cut and what looks good, your drawings can lead you to make bad design decisions and artificially cause you more stress than is necessary without teaching you more about rendering in tile. How To Transfer A Pattern From A Digital Image.

Mosaic Coaster Heart

Mosaic Coaster with Heart Design  was made using a photo of an ox’s heart downloaded from Google Images as the pattern. Is there any doubt as to whether or not this mosaic is an original interpretation? Would anyone try to argue that it is a copy of the photo?

This Method Can Be Used To Make Original Art

What is the alternative to drawing if the beginner is only interested in making original art?

Answer: Select a model from a large number of images (such as hundreds or thousands looked up online or your own photos), and then render loosely with tile on top of that image making simplifications as needed.

This rendering process (“drawing with tile”) can teach you things about the image that the pencil is unaware of. It is a much more taxing interpretation than drawing, and it has its own vocabulary.

Here are the steps for making a pattern quickly from a photo or image,. The details follow. And an explanation about why this method works better than drawing studies of that image.

Make a “Pattern” From A Photo or Image Instead of Drawing It

  1. View a large pool of images, such as can be had in Google images, your own photos, books, and encyclopedias.
  2. Select an image with strong lines and iconic shapes.
  3. Modify the image as desired. Combine multiple figures if desired.
  4. Convert that image into a black and white image. (Photoshop or photocopier or tracing or sketching.)
  5. Resize the image to the size of the mosaic backer.
  6. Transfer the pattern to the backer.
  7. Render LOOSELY on this pattern making simplifications as needed.

I have written a separate article about How To Transfer Mosaic Patterns,

Resize Digitally or Using The Grid Method

Mosaic patterns can be resized digitally, but I have written some instructions for resizing a mosaic pattern using a grid while you copy it onto your backer board.

Combine and Modify Images

You can combine figures from different photos by drawing or tracing them and then cutting them out and gluing them together in collages, or you can do it digitally in Photoshop or other image editors. I prefer the digital method because you can resize the different figures as needed before combining them in a scene.

Making Black and White Copies of Photos

Photoshop is also useful for converting images to black and white without making the images too dark. Use Photoshop’s Adjust Sharpness tool and Adjust Brightness/Contrast before using Photoshop’s Convert To Black And White so that the black and white image is created has maximum contrast. That will help make the image be more outlines than dark shapes, and we need distinct outlines to transfer the pattern onto the backer.

An Example Mosaic Pattern

Here is what a mosaic pattern might look like when derived from a color photograph:

Mosaic pattern Photoshop

Photoshop was used to crop out a detail of Franz Marc’s fauvist painting “The Large Red Horses” and convert it to a black and white image that emphasizes outlines. The outlines and curves are what you want to transfer to your mosaic backer.

In Defence of Drawing

Drawing a pattern by hand or by using the grid transfer method is a great exercise because it enables you to become familiar with the lines and see the image in your mind. Drawing also is an opportunity to interpret what you are seeing and make original art. In fact, for someone like me, the drawing becomes an end unto itself and almost immediately has more detail than can be rendered in the size of tile I will be using.

Drawings As Maps To Nowhere

Overdrawing the details is just part of the problem. The more time spent drawing a pattern, the more likely the artist is to try to hold to it religiously rather than improvising more freely with the tile when needed. This makes the actual mosaic work more tedious than it needs to be, and it can result in awkward results when you attempt a detail in a way that doesn’t take into account the work lines of the tile or what shapes are being used or some other aspect of the tile.

Staying true to carefully rendered patterns can have you scraping off gluey tiles and redrawing the detail in a way that matches the flow of the tile –or pulling tiles off your mesh, mounting tape, or tile paper. I call this mistake “Following the pattern into a detail that can’t be rendered,” and it can happen even when you work indirectly and lay the mosaic up in advance.

Of course, this doesn’t happen often on large mosaics where the tiles are tiny compared to the details being rendered, but for small mosaic plaques and icons, the resolution issue affects nearly every single tile.

How Patterns Should Be Used For Small Mosaic Images

Don’t be a slave to your pattern. Don’t let your pattern interfere with the tiling process and the rendering that happens there. The easiest way to do that is to not become emotionally invested in your pattern, and many artists cannot do this very well with their own drawings. Avoid the issue by using a photo or borrowed image as a starting point. Draw with tile, not a pencil.

Ethical Considerations?

The “Mosaic Coaster with Heart Design” shown above was made using a photo of an ox’s heart downloaded from Google Images as the pattern. Is there any doubt as to whether or not this mosaic is an original interpretation? Would anyone try to argue that it is a copy of the photo?

Look at the width of different features in terms of tile count. Most everything is one or two tiles wide. How would drawing the photograph help a novice make those design decisions? Wouldn’t a novice be better off improvising on a copy the photo itself? Wouldn’t anyone attempting to draw a meaningful pattern need an experienced eye for how the tile can be cut and arranged?

Choosing Mosaic Colors Based On Contrast

Recently artist Jill Miller emailed me wanting some advice about choosing colors for a mosaic table top she was making, and the design she was a chickadee bird with holly leaves and berries. From her photos and a description of the colors she wanted to use for the border of the round table top, it was obvious that she wanted to use muted colors instead of intense colors. I was happy to help. I thought her project was a great example for how to choose colors for backgrounds and making sure there was adequate contrast between the different elements.

Chickadee Mosaic Table Top

Chickadee design for mosaic table top with some candidates for background color. Note how the faint moss green selected for the holly leaf does not adequately contrast the underside of the bird. Notice how the same can be said of the muted brown tile directly under the bird. The orange tiles do contrast the bird, but it is problematic to have a background color that is more intense than the colors of the figure in the foreground. Also, cool colors are usually used for backgrounds because cool colors recede while warm colors come forward visually.

Whether muted colors or intense colors are used, it is still important for there to be contrast in the colors that define different elements, else the elements don’t stand out from one another.

TIP: You don’t have to glue tiles down to see if they are the right color. You don’t even have to position them carefully. Just spread them roughly where they should go, take a break, and then look at the mosaic later. The loose tiles will either contrast the image enough to make the figure stand out, or they won’t. Your fresh unbiased eyes won’t lie to you. Don’t try to rationalize a color that doesn’t work based on some design you have in mind. Listen to your art. Look at it and really see it.

Color Study Version 1

Mosaic Color Study Version 1

Mosaic Color Study Version 1 with intense green vitreous used for holly leaf. The problem with the vitreous green isn’t that the color is too intense but that it is grainy while the other colored tiles are glassy. Also, the green is a little more intense than the color scheme Jill had in mind.

Each work of art is just one version of many potential variations that could have been made with the same design. While it is not critical that you stay true to your original vision, it is important that you don’t have competing versions trying to exist in the same composition. The most important thing to stay true to is the design that is taking shape and making sure that color choices are internally consistent.

Color Study Version 2


Mosaic Color Study Version 2

Mosaic Color Study Version 2 with moss green for holly leaf. This more intense moss green still isn’t intense enough to adequately contrast the bird. Also, the color choices for the Chickadee are true to life, while this color green for a holly leaf is not. Again, colors don’t have to be true to life, but they do need to be internally consistent. A work of visual art can be a world unto itself, but it does need its own internal logic.

Color Study Version 3

Mosaic Color Study Version 3

Mosaic Color Study Version 3 with mint green for holly leaf. “Ah, said Goldilocks, this third bed is just right…” Notice how this mint green teal color has enough intensity to contrast the colors in the Chickadee yet still keeps with the artist’s vision of muted colors. I like it. The muted colors remind me of an Audubon print, and what could be more appropriate for a picture of a bird?

Wrong Color? All Is Not Lost.

Most beginners are so eager to begin work that they start gluing down tiles before they are sure they have the right color. Usually they don’t notice that they don’t really like the color until they have spent an hour or so mounting tiles in glue. If that happens, all is not lost. Put on some work gloves and safety glasses  and scrape up the tiles with a screw driver. Soak them in water to remove glue residue. If the glue has already hardened for several days, you may break some tiles while scraping them up. If so, use a vacuum to pick up sharp slivers. Moistening the tiles for 30 minutes with a cotton swab dipped in water can help soften glue, but it can also increase the risk of creating gouges and delaminations in plywood backers.

Color Wheels and Complementary (Contrasting) Colors

Color wheels are an artist’s tool for choosing complimentary colors, which are pairs of color “opposites” that provide maximum contrast to each other: red and green, orange and blue, yellow and purple. Those are the main pairs of opposites, but the hues in between also have opposites. For example: blue-green and red-orange. Color wheel charts position all of these opposites directly across the wheel from each other, which makes it easy to see what the optimal contrast would be for any given hue.

You can see some color wheels by searching Google for “color wheel” or “complimentary colors.” Some are more in depth than others. I like the ones that also show different options for value, which is the relative lightness or darkness of the color.

Intense Colors and Contrast

Contrasting colors are important because they make images stand out. Look at these great bird mosaics made by Phil Lamie’s elementary school students, Notice how these mosaic take full advantage of contrast between intense blues and warm oranges. Notice how the cool blues are usually in the background and the warm colors are in the figures in the foreground. In the case of the blue bird, notice how the blue in the bird in the foreground is more intense than the blue of the sky in the background. Value and intensity can be used to make foreground images stand out from backgrounds, as the blue bird mosaic demonstrates. All of these bird mosaics are visually striking because they follow basic rules of using color.



Mosaic Pizza Oven

Mosaic Fireplace and Oven Surrounds: The Basics

A couple of years ago, I wrote a page explaining how glass, ceramic, and stone tiles can be used for mosaic fireplace surrounds and how the tiles should be mounted with thinset mortar or white PVA (polyvinyl acetate) adhesives such as Weldbond. But we are talking about the SURROUNDS, not inside the firebox. For inside the firebox, your need to use refractory materials (brick or stone) that can resist combustion temperatures. For the hearth, the issue is not temperature resistance so much as impact resistance: It doesn’t make sense to use glass tiles that are easily cracked by a metal poker or small tiles that are easily knocked loose. Stylistic concerns should never outweigh performance and durability, else the work won’t look good for long.

Mosaic Pizza Oven

Mosaic Pizza Oven by artist Kristina Young with octopus tentacle motif. Seafood and sea life and undersea scenes were common themes of Roman mosaic.

Problems with a Mosaic Pizza Oven

Recently, artist Kristina Young emailed me concerning a problem she was having with a mosaic she installed on the outer surface of an Italian pizza oven. The problem was that the mosaic was cracking over the door of the oven, and that caused me some concern because that should not happen with traditional fireplaces and pizza ovens constructed with brick or stone, and I have been telling people for years that there was no reason why they could not put mosaics on these surfaces in spite of the heat. Had I overlooked some basic technical principle and made recommendations that could ruin hundreds of people’s projects? The engineer in me became completely paranoid, and I could not wait for Kristina to email me back with answers to my initial questions.

Spoiler Alert: The good news is that the cracking is reparable and that the cracking is by the iron frame of the oven door, not the masonry elements of the oven itself, which means that there is no reason to expect similar problems with traditional fireplaces and ovens that are made from all stone or brick or concrete.

The Case of the Cracking Mosaic

cracking mosaic detail

Detail shot showing crack in brand new mosaic covering the exterior of masonry pizza oven. The location of this crack is significant: It started  right above the iron frame of the oven door.

When Kristina first contacted me, she was concerned that the cracking might have been caused by heating the oven not long after the mosaic was completed. That is a potential issue because thinset mortar takes time to harden, and like concrete, it hardens by bonding moisture not by drying out. (Concrete, mortars, grouts, and other portland cement products will be soft and crumbly if they are dried out by heat or dried air. They need to incorporate the water mixed into them, not have it removed artificially.)

Humidify, Don’t Heat

I don’t think that the oven was heated prematurely or that premature heating caused the cracking. The crack is location specific, and if the mortar was artificially dried out before it could harden, then the problem would be seen all over the mosaic in the form of cracks and missing tiles. That being said, I would avoid heating fireplaces and ovens for several days after a mosaic has been applied to them and grouted. The usual practice is to run humidifiers near a new mosaic to protect them from AC or central heat –not build a fire under them!

Thermal Expansion

Except for the notable exception of ice, most materials expand when they are heated. (Water expands when it freezes, and that is why ice floats: it is less dense than the water beneath it.) The problem with thermal expansion is that materials expand at different rates, and metals like iron expand more rapidly than stone, brick, and concrete. Kristina had already told me that the crack started on the front of the oven just over the door, and so as soon as she sent me a picture of the oven showing that the door had an iron frame, it was obvious to me why the crack had started there: The glass and mortar mosaic expands at roughly the same rate as the brick and concrete oven underneath it, but the iron door frame and the other iron structural elements expand even faster. They push the mosaic up like a shell on the outside of the oven, and when the oven and frame cool back down and contract, the crack appears.

The Right Repair Materials

An “expansion joint” spontaneously forming in the middle of your mosaic might have most people panicking and thinking of repairing the crack with a flexible material such as caulk. Caulk is problematic because it will not age well. It will yellow and shrink and crack. It will look more and more like the synthetic material that it is, a material that looks out of place on tile, a material which does not age.

Grout could be used to fill the crack. After all, grout is the concrete product that is used to grout gaps between tiles in the first place. However, thinset mortar is a better choice because it is harder and tougher and more adhering than grout,, and it can tolerate slight displacement (movement) while grout cannot. In fact, it would have been best if the entire mosaic had been “grouted” with thinset. I suspect that heating and cooling the oven in cycles over time may cause other cracks to appear or reappear, and these should have thinset rubbed into them as needed. Hopefully any new cracks or reappearing cracks will be smaller, but in any case, thinset is better equipped to withstand the stresses of expanding and contracting than grout.

Mosaic crack repaired with thinset mortar

Mosaic crack being repaired with thinset mortar. The mortar is spread on and worked into the cracks and wiped off just like grout. Thinset is superior to grout because it is harder and tougher and can tolerate slight movement.

Aesthetics and Authenticity

Think of high-end restaurants in reclaimed urban warehouse spaces: the exposed beams, the plaster chipped away in places to reveal the stone walls underneath, the different architectural elements like fire doors and hoists deliberately left in place to call attention to the space’s past industrial use.

To me, one of the more interesting things you can see in the mosaics of Mexico and the Mediterranean basin are the repairs that have been made to these over the years following earthquakes and other damage. I’m not thinking of the repairs that were made in modern times by archaeologists or professional conservators sparing no expense to make the mosaic look as if the damage had never occurred. I’m thinking of repairs made in the distant past by inexpert hands or by people with limited access to materials. I’m thinking of repairs like mortar-filled voids and replacement tiles of not-quite-the-right color and how you can sometimes see a series of these inexact repairs apparently made at different times in response to different injuries. To me, these inexact repairs more than anything else give me a sense of how ancient the mosaics are and how much history they have witnessed, endured even: earthquakes, fires, wars with slings and arrows, wars with bullets and bombs.

A large part of the ethos of mosaic art is it being an enduring relic of the past. If I were wanting to design a mosaic to look like an old relic, I might consider deliberately including mortar-filled voids and cracks to simulate past damage or maybe re-mosaicing some of these regions with coarser tile. With that in mind, is a crack appearing in a new mosaic in an Italian or Mexican restaurant a problem or a windfall? I’m thinking not. I’m thinking of the kid who deliberately scuffs up his new baseball glove so that it doesn’t look the unused glove of a rookie.




Mosaic Guitar

Artist MC Holt-Evans of Nashville recently made a mosaic sculpture very much in keeping with spirit of The Music City, and her mosaic guitar is worth taking a look at, especially if you are considering making a mosaic on an improvised base such as a musical instrument or a piece of furniture. The instructions below could be adapted for using other household objects as a base.

mosaic guitar back side

Mosaic guitar by MC Holt-Evans has a “blue grass” color scheme.

Mosaic Sculptures on Improvised Bases

Mosaic sculptures that use household objects as their base aren’t anything new. For example pique assiette (broken plate) mosaic furniture is fairly common, as are mosaic gazing spheres made from bowling balls. (Note that my article on gazing spheres explains why hard polystyrene makes a better base than a bowling ball.) However, a guitar can be a particularly challenging choice of mosaic base for several reasons: The shape is complex and curved, and part of it (the neck) is long and thin and has a lot of corners. The wood of the guitar’s sound box is thin, and yet it has a thick layer of lacquer that must be removed before adhesives and grout will bond to it.

Prepping the Guitar


A medium grit sandpaper (120 grit) can be used to take off any lacquers or sealants. As always, wear an N95 rated dust mask for doing this type of work. (The N95 dust masks are cheap and readily available at a building material or hardware store.) I don’t recommend wet-sanding a guitar because you want to minimize its exposure to moisture until you get it sealed because the wood is thin and easily warped by moisture.


Are you going to want to put the strings back on the guitar after it is mosaiced? Probably so, and that mean you need to take into account the thickness of the tile you are adding to the surface and raise the nut fret that separate the head from the neck. Use a hard wood for this such as bass (the wood used for sewing boxes and buttons) and not some soft wood like balsa.


When you reseal the guitar with a water-based primer, you should apply two thin coats instead of one heavy one. To seal her guitar, Holt-Evans used an acrylic primer called Zinsser’s Bullseye 1-2-3 because it was recommended by an artist who works with mosaic guitars. Weldbond adhesive could also be used to seal/prime a guitar, and it might be the better choice because it is the adhesive that will be used to attach the tiles, and thus you wouldn’t have to worry about how well the adhesive and primer bonded to each other, but you would still need to give the sealing coat at least a week to dry out completely and fully harden before you tiled on it. Holt-Evans reported that she left coarse brush strokes in the sealant. This improves the bonding of adhesives and grout.

Using What You Have on Hand?

Be careful selecting a primer at random because Weldbond might not bond to some of them, definitely not oil-based materials. You want an acrylic, something like an artist’s gesso and not a latex house paint. PVA’s like Weldbond won’t bond to the vinyls and other binders in some house paint. Using what you have on hand isn’t necessarily being frugal if it doesn’t last nearly as long as it would have with the right stuff.


The wood of the guitar was sanded bare and sealed with an acrylic primer in preparation for mosaic covering.

Mounting the Tile

Holt-Evans used Weldbond to attach the glass tile, penny rounds, and stained glass she used.

Partially Crushed Liquor Boxes

Use partially crushed liquor boxes to cradle the guitar or sculpture while you work on it. You can rearrange the boxes to re-position the guitar as needed so that whatever part of the curved surface you are working on is facing up.

Brush on the Adhesive and Let It Get Tacky

If you are having problems with tile sliding around, use a small paint brush to spread the Weldbond onto the surface and allow to sit for a few minutes and get tacky before you add the tile. Depending on how dry or moist your air is, this can be about 15 minutes, perhaps much faster if it is dry midwinter air and the heater is running. Remember, if you let the glue skin over too much, then it won’t bond to the glass as well.

Dental Picks and Cotton Swabs

Dental picks (or tooth picks) are invaluable for adjusting the positions of tiles without contaminating your fingertips. Cotton swabs can help clean up messes with precision and not move tile out of position. Tip: Don’t thow your wet-glue swabs into the trash. Instead, let them dry out and peel the dried glue off them next session and get another life out of them.


Mounting the tiles on the primed surfaces of the guitar.


Grouting Studio or Bench Space

I like to grout outside on a patio or some place that can be hosed off. You can use drop cloths indoors, but you still have to be relatively neat, or you will track sand on the floor and ruin it. Grout and thinset mortar are concrete, not paint. That being said, grouting inside can be done without making a mess and is routinely done by mosaic artists. A plastic folding table or a table covered in construction plastic from the building material store is ideal for a project that might require multiple sessions to grout.

Grout Colors

Black grout makes color stand out more. All grout colors are lighter when the grout hardens, especially black grout. Black grout is usually jet black when mixed up but hardens to a charcoal gray or lighter. Pure white grout makes a mosaic look like a summer camp project.

Thinset Mortar vs Grout

I prefer thinset mortar instead of grout for projects like these. Thinset has an adhesive polymer in it that makes it strong and resistant to impact. Compared to ordinary concrete and grout, thinset is a lot less likely to crack and crumble when dropped. However, thinset contracts slightly as it cures, and so you might observe hairline cracks when used on a three dimensional object that can flex slightly, such as a wooden guitar. Like grout, thinset mortar can be dyed with concrete dyes.

Special Concerns

Grouting something like this is best done in multiple sessions. Unlike a mosaic chair or desk, a guitar has multiple places where special are has to be taken in order to not soil or clog some detail. A guitar has frets and working pegs and a saddle and a sound hole to take into account. Painter’s tape can be used to protect the bare wood inside the sound hole. Use crushed liquor boxes to cradle the guitar in different orientations while you grout it.

The color of a grout can look different if different amounts of water are used to mix up different batches or if they are misted differently. Try to mix up and handle your grout in a consistent way.


Finished mosaic guitar by artist MC Holt-Evans.

Grouting Sequence

Holt-Evans started by grouting the back of the guitar because it was the largest flat area with no obstructions and therefore the most straightforward surface to be grouted. When she grouted the back, she continued the grout over the sides so that there wouldn’t be a grout seam right at the corner because corners are vulnerable places and subject to many impacts.

The head and neck were each done in separate sessions, and for both of these elements, Holt-Evans did not take the mosaic and the grout around to the sides and backs. Only the top faces were covered, and so this meant that the grout had to be tapered off to the corner.

The front of the guitar was done in a later session because of the detail work required to get the grout tapered to the edge of the sound hole. The grout was carried down over the side to join the grout from the back on the sides.

To prevent a hairline crack where new grout meets the old, you should moisten the edge of the old grout with a little water on a cotton swab before grouting. This keeps the old grout from sucking all the water out of the new grout before it has a chance to harden.

Small Glass Mosaic Instructions

These instructions explain how to set up and make a small mosaic from glass mosaic tile. I use our new hardwood mosaic coaster bases with 12mm Elementile recycled glass mosaic tile as an example, and I show how to set up your studio work space in ways that control dust and sharp splinters of glass. I grew up working in a dirt-floor welding shop and have spent a lifetime thinking about ways to minimize my exposure to potentially harmful substances, especially dusts, so don’t let my emphasis on safety alarm you.

These instructions were also written for someone trying to fit the glass as close together as I did in my mosaic crab shown below. If you leave an irregular grout gap of 1/16″ or less, you will have to cut a lot less and create fewer shards and dust. (You will also be able to use nearly every piece you cut and be able to use regular sanded grout to grout it.)

mosaic coaster crab

Crab Mosaic Coaster. I used the glass mosaic tile upside down so that the embossed texture showed to make this crab. The edges of the coaster were smoothed with a marble file. Note that leaving a gap for grout instead of fitting the tile together this closely would have made the work infinitely easier. Fitting tile this closely takes more trial and error and you may end up cutting up over twice the amount of tile than you actually use. Most of these extra pieces could be eventually used on a future mosaic, but you can really take a lot of stress out of the process by leaving irregular gaps and not fitting each piece exactly. You can make the tile touch in places and still have an irregular gap.

Mosaic Studio Set Up

Mosaic Studio Set Up

Whether you are painting, soldering, sewing, engraving or doing mosaic, your workspace tends to evolve into a U-shaped station where you can reach everything you need. Note the trays made from cardboard shallow boxes holding tile in recycled yogurt containers. Keeping your materials in shallow boxes and trays allows you to set up different activities and clean up quickly. One of the most important pieces of equipment isn’t shown: a HEPA-quality vacuum for cleaning up splinters of glass and any incidental dust.

Your Vacuum Needs To Be A HEPA Vacuum

Your home vacuum should be HEPA quality, which means it removes at least 99.97% of airborne particles 0.3 micrometers (µm) in diameter. I say this for all uses including cleaning your house and not just for mosaics or other crafts. If your vacuum isn’t HEPA, then it is blowing out a lot of dust that you are breathing. Vacuuming should make the air more healthy to breath, not expose you to lots of dust. Keep in mind that the silicon dust you track in as soil can be just as bad for your lungs as most of the materials used in arts and crafts.

When you cut up glass mosaic tile, there will definitely be small vicious splinters of glass that hide unseen on surfaces until you slide your hand across it and get a nasty cut before you even know what bit you. A vacuum and a counter brush are good ways to remove these from the work surface and the surrounding floor and to pick up any dust that is created by cutting.

Cutting Towel and Spray Bottle

cutting towel for glass slivers

An old dish towel or hand towel can be used to catch tiny splinters of glass created during cutting. Be careful shaking the tile out after use because you could flick sharp pieces of glass. We do this INSIDE a large garbage can and wear safety glasses when we work with mosaic. You should also mist your towel before shaking it to make sure you are not creating airborne dust.

In addition to a vacuum, you should use an old dish towel or hand towel to contain any dust and splinters created by cutting tile. You can put the towel in a shallow box or dishpan to catch any pieces that fly off when nipped by the mosaic glass cutter. The towel and tile can be misted with a spray bottle to prevent the formation of airborne dust, but don’t be excessive. You still need to keep the moisture away from the vacuum to prevent the risk of electric shock, and moisture can cause wood backers to warp, especially thin wood such as the mosaic coaster bases.

Using Marble Files Without Creating Dust

Marble File in Bucket

Marble files are great for shaping individual tiles and smoothing the edges of finished mosaics, but they should be used in an intelligent way that doesn’t expose you to glass dust. We do this by keeping the file in a 2-gallon plastic bucket and misting with water from a spray bottle. Sure the file will rust over time, even if you rinse and dry it each night, but marble files can be replaced while new lungs are hard to get. You already breath enough silicon from pulverized sand every day merely by living on planet Earth. Don’t add to the burden through your hobbies.

Mostly you can get the pieces you need by nipping, but sometimes there are random slivers left at the edge of a cut, and the edges of the finished mosaic on a round coaster base usually requires smoothing. Now any blockhead can just grab the file and go at it, but I LIVE in my studio, so I use common sense practices such as wet sanding and wet filing to make sure I don’t create airborne dust. Use your marble file in a 2-gallon plastic bucket and mist with a spray bottle to contain the dust at the source.

Mounting Tile With Glue

Tweezers and glue

Tweezers and glue. Working with pieces of tile this small is difficult without the use of a pair of tweezers. A self-closing pair of tweezers with a needle point is shown, but these can sometime cause a tile to shoot out, and I prefer regular tweezers with a wide tip.

We use the Weldbond brand of white PVA adhesive because it is the best PVA we have used and doesn’t get as brittle in cold temperatures as some of the other brands we have tried over the years. It also seems to be very water resistant when fully cured. (Note that water resistant does not mean water proof, and we use thinset mortar on all wet mosaics and outdoor mosaics.) The white disk in the photograph is a top from a plastic yogurt container. We use these to hold a small blob of glue and dip the bottom of the tile into the glue using a pair of tweezers.

If you are fitting the tile tightly together, make sure you start at the center of the mosaic and work outwards. Otherwise, you can warp thin wood backers by squeezing tile into tight places.

Drawing Mosaic Patterns On Your Backer

Draw the cartoon (outline) of your mosaic directly on the coaster base or whatever small mosaic backer you choose. You should start with pencil and then darken the principal lines with a fine-point marker such as a Sharpie. Your pattern should look like a picture from a coloring book: just the main lines and the outline of the figures.

You can also find a pattern on paper and transfer the pattern to the backer using graphite tracing paper (carbon paper). First, print the pattern as the same size as the backer by resizing the pattern using a photo-editing program. Then tape the pattern to the backer with carbon paper in between the pattern and the backer. Then trace over the pattern firmly with a ballpoint pen.

If you cannot print the pattern the same size as the backer, you can use these instructions for enlarging and transferring a mosaic pattern.

Grouting The Mosaic

Most mosaic art is made with a grout gap of roughly 1/32 inch to 1/16 inch and is grouted with sanded grout. If your mosaic is made with fitted tile such as mosaic crab coaster above, you should use nonsanded grout or leave the mosaic ungrouted. Note that leaving a mosaic ungrouted is not practical for wet mosaics and outdoor mosaics or even mosaic counter tops. Those mosaics need grout to seal out water.

You should mix your grout according to manufacturer instructions, which usually specify roughly 1/4 pound of water per every 1 pound of sanded grout, and mix it thoroughly to make sure all the powder is thoroughly wetted. The grout is applied by smearing the wet grout across the face of the mosaic, and you should make several passes from different directions to make sure the wet grout is being forced to the bottoms of the gaps and not just superficially covering the tops. A gloved hand is good for this work, but be aware that sharp edges of cut tile pieces can sometimes cut through a glove. That is why the grouting gloves we sell are thicker than most dish washing gloves. You can cut a plastic lid in half to make a great disposable grout spreader.

Make sure you don’t allow the grout to dry out as it as curing. Concrete hardens by BINDING water not by drying. If you have to, cover the mosaic in plastic wrap or use a humidifier. Both are recommended if you are in a dry climate or the heater or AC are running excessively.

Make sure you use a damp (but not dripping) sponge or rag to remove excess grout from the face of the mosaic, but be careful not to pull the grout out from the gaps between the tile. After grout has hardened, you can buff the face of the mosaic with wet and dry rags to remove any remaining haze.

Dispose of your wet grout in the trash and not sinks or drains. Grout is concrete and can harden underwater, and even the loose sand can be a problem is pipes.

Outdoor mosaics and architectural mosaics (such as counter tops and backsplashes) need to be sealed with a tile and grout sealer such as the TileLab brand from Home Depot, but small art mosaics don’t really require it unless you expect it to be subjected to splashes and stains.

Additional tips about grouting can be found on the mosaic grout page and our page for how to avoid grouting problems.

Sealing Sides and Backs Of Wooden Backers

I like to seal the side edges and backs of wooden backers with a clear polyurethane (sometimes with varnish, sometimes without) or with acrylic artists paint such as umber or burnt umber.

This keeps the plywood from delaminating and solid wood (such as the coaster bases) from cracking or warping. This is particularly important for coasters subject to spills and condensation from glasses.

Mosaic Transfer Instructions

Yesterday I wrote up some recommendations and instructions for Outdoor School Mosaics that focused on a project where each child made a mosaic stepping stone on a paver to be arranged in a crazy quilt design. I forgot to clarify that those instructions were written for younger students and beginners needing to play around with tile and get some basic experience forming tile into patterns and shapes. After all, it doesn’t make sense to have young children trying to copy the work of an experienced mosaic artist before they have had the benefit of handling tile long enough to make a simple triangle or smiley face.

More Sophisticated Designs

If you wanted to use make a more sophisticated design with smaller pieces of tile or to render an image, you could adapt that same method and add just a few steps. I have the steps numbered below, but here is a summary of what would be different: Before you covered the cardboard square with contact paper (sticky side out), you would draw your pattern on the cardboard or tape the pattern to the cardboard. Once you position all your tile on the pattern covered in contact paper, you would use some mosaic mounting film to pick it up off the cardboard/contact paper. Then the mosaic could be pressed onto a paver or stepping stone coated with thinset. Once the thinset hardens, the mounting film is peeled off and the mosaic is grouted. This method allows you to lay up very complicated designs in advance of transferring it all at once to the cement.

Pavers vs. Molds

Note that here I am talking about using thinset mortar to attach a mosaic design to an existing stepping stone or paver or flagstone. If you need instructions for how to use a stepping stone mold to press tiles into wet concrete (or pour wet concrete over a mosaic design mounted on contact paper at the bottom of a mold), then read my article on Mosaic Stepping Stone Instructions.

Stepping Stone Transfer Instructions

  1. Cut out a square of cardboard the same size as your stepping stone or paver. If you want to use an irregularly shaped piece of flagstone as your mosaic base, you can cut out a piece of cardboard in the same shape as the flagstone. Just lay the flagstone on the cardboard and trace around it.
  2. Draw your mosaic pattern on the cardboard or on a piece of paper taped to the cardboard.
  3. Wrap the cardboard pattern with clear contact paper with the STICKY SIDE OUT. The sticky contact paper keeps the tiles from sliding around as you position them on the pattern.
  4. Use mosaic mounting tape (or clear packing tape) to pick the mosaic up off the cardboard pattern.
  5. Coat the paver or stepping stone or flagstone with a thin layer of thinset mortar. Smear it around to make sure the surface is wetted thoroughly and then scrape off the excess. You only need a layer about 1/16 inch thick. A little more won’t hurt, and it doesn’t have to be exact, but too much can be a little messy if you press down of the mosaic and squeeze it out the sides.
  6. Press the mosaic into the thinset. It may be easier to lay the mosaic on a table (with the mounting tape side down) and lower the thinset-covered stone onto the sheet of tile.
  7. Allow the thinset to harden for 24+ hours.
  8. Peel off the mosaic mounting tape.
  9. Grout the mosaic with additional thinset if needed. It is better to use more thinset instead of grout because it will match the color of any thinset that pressed up between the tiles when you mounted the mosaic. If you use grout, then the color probably won’t be exactly the same, and your mosaic will look like you grouted it with two different types of concrete. Often no additional grout is needed because enough thinset squeezes up between the tiles during mounting.
  10. Clean any grout residue or haze from the face of the mosaic by buffing with a clean cloth.
  11. Allow the grout to cure for 2 or 3 days and then seal the finished mosaic with a tile and grout sealer purchased from a local building material store.

For more information on using clear contact paper and mosaic mounting tape to lay up and transfer mosaic designs, read my article on Mounting A Mosaic On Clear Adhesive Film. If the cost of mosaic mounting tape is too high, or if you don’t need a whole roll, then you can use clear packing tape as a substitute.

How To Cut Marble Small

Recently a customer emailed me asking how to cut a piece of marble mosaic tile into very small pieces. He reported that he could easily cut the marble tile into thirds by making straight cuts, but when he attempted smaller pieces or diagonal cuts, the marble would crumble or break into jagged pieces

The customer verified that he had the correct tool for cutting extremely hard tile, which is a compound nipper, but the problem is in the stone (and the technique to a certain extent) and not the tool. This article explains how to make cuts that take into account natural breaking points in the stone and how to use a marble file to file down extra small pieces instead of cutting.

Homogeneous And Thinly Layered Stone Types Cut Better

Whether or not a piece of stone tile can be easily cut into small pieces depends on the type of stone. Some varieties can be cut into thin sections while other varieties are likely to crumble or break irregularly when cut to any size. This is due to the internal structure of the stone. If a stone is homogeneous or composed of many thin layers, then it probably can be cut into thin pieces without breaking randomly. But other types of stone have veins and globs and swirls, and these types are likely to break along these natural internal structures instead of the intended line between the blades.

Note that some types of stone have natural swirls of color that do NOT act as natural fault planes, so you can’t always assume a stone will be difficult to cut reliably merely from variegated color.

Take Veins, Globs, Swirls And Layers into Account

With practice and experience, you can learn to look at the veins, globs, swirls and layers in the stone and make your cuts in places where the stone is likely to break naturally. Just as an experienced carpenter knows to avoid diving fasteners into knots in wood, an experienced mosaicist knows to make cuts along natural boundaries. Even then, there are still some varieties of stone where scrap has to be generated to get small pieces by cutting. However, there is a way to make small pieces from difficult stone types

File Instead Of Cutting

For problematic varieties of stone, you can use the fine side of a marble file to file a piece down to size instead of cutting it. Of course, you may need to make an initial cut with a tile nipper to get the stone to a manageable starting point before using the file. In fact, you may discover a lot of useful starting pieces in the “useless scrap” created by previous cuts.

Once you get accustomed to using a marble file, you may start to think of rough cuts as just an initial step followed by shaping with a marble file. For really small pieces, you can completely alter the shape of the tesserae with just a few strokes because all of the abrasion is focused on such a small surface area. You should hold the file still and rub the stone on the motionless file for greater control.

Tip: Wear gloves for this task because it is difficult to slide the tiny pieces up and down the file without scratching up your fingertips. If gloves make your hands too clumsy, then use a shop rag over your fingertip instead. As always, use mist from a spray bottle to control dust and wear a dust mask if needed.

Of course, this isn’t a scalable solution, meaning you wouldn’t want to have to do this for very many tesserae, but it is useful for making a limited number of small pieces for fine details in a mosaic mainly made from larger pieces.

Plan Mosaic Designs Starting At The Smallest Detail

Sometimes the best way to deal with a problem is prevention. It doesn’t make sense to start with a mosaic pattern that has details smaller than the smallest piece of tile you can cut, but many novices make this error, which often results in a key focal point of the mosaic being more crudely executed than the background. Instead of assuming that you can always just cut the tile smaller to make the smallest detail of a mosaic, do the exact opposite: Before you begin executing the mosaic, take the smallest detail of your design and try cutting and arranging a few tiles to make that detail. If the tile is too difficult to cut that small, or if it is too tedious to arrange properly, then consider making the mosaic larger (or simplifying the smaller details of the design).

The size of a mosaic (or a painting) is ultimately determined by the size of the smallest detail that can be rendered. The principle seems obvious in hindsight, but in practice it catches many people by surprise. Why? Because they can visualize the smallest detail easily but do not realize that their powers of execution are much more limited.

Take the stress out of your mosaic project by playing with tile before you begin. Cut a little bit of it up and play around making patterns, and then decide how detailed your design should be and how large it should be. If your total area is already fixed (due to the size of an existing surface to be tiled), then try cropping or simplifying your design.

Mosaic Stepping Stone Instructions

Mosaic stepping stones are great first projects, but they don’t have to be cheap and cheesy or dangerous. Keep in mind that if you totally cover the surface of the stone with large pieces of stained glass, it is likely to be slippery when wet. If you leave sharp edges of glass exposed, or allow the grout to erode out from between the glass over time, then your stepping stone is less of a stepping stone and more of a device for cutting bare feet. Both of these problems can be avoided by following best practices and using sound methods.

A Brief Rant

First, avoid the craft kits that have you make a butterfly or some other canned 1970s design by gluing large pieces of pre-cut stained glass onto a stepping stone. Glue will not resist moisture over time, and these kits are the poster child of slippery when wet. They also look exactly like all the other mass-produced stepping stones from China and thus have all the charm of a fast-food wrapper or billboard.

Instead, make something original by pressing your own designs of small tile into wet concrete, and be confident that whatever skill you lack may actually add to the originality and charm of what you make. A homemade stepping stone is supposed to look like a homemade stepping stone and not something made in a Chinese prison factory based on a design first copied in the 1970s.

Glass Tile Is Best

Glass tile doesn’t have any pores, and so water can’t penetrate into it and freeze and crack it. Ceramic materials have lots of pores, and there are tiny cracks in the glazing, so these materials are more susceptible to freeze damage. However, porcelain and dinnerware and other high-end ceramics are a lot more resistant to freeze damage than something like glazed bathroom tile, so they can be used with discretion. Remember, the more soft or crumbly a ceramic material is, the more susceptible it is to freeze damage. Avoid terracotta, glazed ceramic bathroom tile and anything that easily breaks.

Decide Which Method To Use

There are two main methods of making a mosaic stepping stone. It is better to use a mold if you are wanting to use marbles or large stones or other found objects not easily attached to a flat surface.

1. Prefabricated Stepping Stones.

You can cement tile to a plain prefabricated concrete stepping stone purchased from a lawn and garden center.

2. Stepping Stone Molds.

You can press tile into wet concrete in a stepping stone mold or have a mosaic design on contact paper at the bottom of a stepping stone mold and pour concrete on top of that.

Note that both methods require that you mix up a powdered concrete product because you cannot use glue to attach tile to an outdoor or wet mosaic. Instead, you have to use thinset mortar, which is a powdered portland cement with polymers added for enhanced adhesive properties and strength.

Prefabricated Stepping Stones

Plain concrete stepping stones can be purchased from lawn and garden centers. These make great bases for mosaic stepping stones even if you are wanting to press tile into wet concrete instead of cementing the tile to a rigid surface and then grouting later. How is this possible? Easy. You simply spread the mortar on a little thicker than normal, say about 3/8 inch thick, and press the tile into that.

Stepping Stone Molds

Stepping stone molds can be purchased or improvised from ordinary containers such as plastic dish pans and old metal cake pans from the thrift store. Various websites recommend using the nonstick baking pans from your kitchen and even make the claim that you won’t scratch them up, but I wouldn’t go that route. As a general rule, I avoid using anything from my kitchen in my art studio and then returning it to the kitchen, and I’m fairly sure that some people would manage to scratch the pan when they removed the hardened concrete stone. Besides, you can always get old cake pans from the thrift store or use a plastic dish pan or take an old plastic 5-gallon bucket and cut it down with a jigsaw. There is no reason to raid the kitchen when all these other options are available.

Tip: No matter which type of mold you use, make sure you coat it with non-stick cooking spray or petroleum jelly (Vaseline) to ensure that the hardened concrete stone can be removed easily.Sources of Improvised Molds:

mosaic stepping stone instructions

A stepping stone mold with some accessories. The pea gravel can be mixed with the thinset mortar to give it strength and bulk.

Sources of Improvised Molds:

  • plastic dish pans
  • plastic totes
  • purchased stepping stone molds
  • old cake pans from thrift stores
  • 5-gallon plastic buckets cut down with jigsaw
  • plastic litter boxes (new or bleached)
  • plastic plant trays
  • cardboard boxes lined with plastic trash bags
  • your spouse’s nonstick baking pans (not recommended)

Two Ways To Use A Stepping Stone Mold

There are two ways to use a stepping stone mold. You need to decide which you will use, and the second is better for marbles and other found objects that aren’t flat like ordinary tile:

1. Put the tile at the bottom of the mold and pour concrete over that.

You can place your tile UPSIDE DOWN in the bottom of the mold and pour the concrete on top of that. The easiest way to keep your tile from moving around when the concrete is poured on top is to put contact paper at the bottom of the mold with the sticky side up. Then you stick your tile UPSIDE DOWN onto the contact paper. This method is recommended if you want a very detailed design because it allows you to get all your tile carefully positioned before you mix up the concrete, which only has a few hours of working life before it starts to harden. Even if your design isn’t very complicated, I wouldn’t attempt it without the use of contact paper. Make sure you add the concrete slowly and gently tap the mold as you go along to make air bubbles come to the surface.

2. Press tile into wet concrete at the top of the mold.

This method is best for mixed-media designs made from marbles and other rounded found objects that couldn’t stick reliably to a piece of contact paper. You simply press the objects into the concrete, and you have the advantage of being able to vary how far they are embedded and to see how the work looks as you go along.

Tip: Wait 30 to 45 minutes before you start pressing objects into the wet concrete. This allows the concrete to firm up a little so that your objects don’t sink to far into it.

Using Thinset Mortar Instead of Ordinary Concrete

Thinset mortar mixed with a little pea gravel is MUCH stronger than ordinary concrete.

Most stepping stone instructions say to use ordinary concrete and often have tips about how to pick or sieve the larger pieces of gravel out of the concrete so that they don’t interfere with the tile or objects you want to embed in the concrete. One of the most significant hazards of doing mosaic work is breathing concrete dust, so if you were going to do this sieving or picking, you would want to do it AFTER you had mixed the concrete up, and that seems like a lot of pointless and difficult work to me.

Instead, I buy thinset mortar, which does not contain gravel, and I mix in small pea gravel in a ratio of 2 parts wet thinset to 1 part pea gravel by weight. For example, to make two small stepping stones, I recently used 8 pounds of wet thinset mixed with 4 pounds of pea gravel.

The pea gravel is needed because thinset mortar slightly contracts as it cures (due to the adhesive polymers), and all traditional portland cement products need and aggregate such as gravel or pea gravel to provide tensile strength.

IMPORTANT TIP: Set some of your thinset aside and don’t mix any pea gravel into it. Use this gravel-free thinset for the layer where your tile will be embedded so that no gravel interferes with the tile as you press it in. First, fill your mold about 3/8 inch from the top with the thinset mixed with pea gravel. Then fill the rest of the way up with the plain thinset. That top layer is where you would press the tile without having to worry about pea gravel in the way. If you have a pattern on contact paper at the bottom of the mold, you would first pour in some plain thinset and then top the mold off with the mixture of thinset and pea gravel.

Tips for Using Thinset Mortar

I have written some instructions for using thinset mortar and some tips for keeping your hands and tools clean while working with thinset mortar.

My instructions in those two links are for doing very detailed work with thinset. Most mosaic projects (such as stepping stones) are a lot more simple. Most of what you really need to know about thinset can be summarized here:

  1. Wear a dust mask when mixing up thinset to avoid breathing dust, and mix it up outdoors for easy clean up.
  2. For Versabond brand thinset, we mix 1/4 pound of water per 1 pound of thinset. The package will have manufacturer instructions for how much water to mix in.
  3. You have about 2 to 3 hours of working time provided you keep the thinset covered when not in use. If you are working in conditions of extremely dry air, such as when the heater or AC is running), then use a humidifier to keep the air moist.
  4. Do not dispose of thinset in plumbing or drains. It is concrete and can harden underwater.

Cleaning and Sealing

No matter which method you use, you should wait at least 24 hours before removing your stepping stone from the mold.

Sometimes stepping stones made on contact paper at the bottom of a mold will be removed from the mold, and the artist will discover voids between the tiles due to bubbles. Other times, you will see that concrete has gotten between the tile and the contact paper, and so there is concrete on top of the tiles. Both of these problems are easily fixed.

Voids are filled by mixing up small amounts of concrete and dabbing them in. Concrete on top of tiles can be scraped off using a small screwdriver or other steel tool. Use a spray bottle to mist the stone as you work to control any dust.

A few days after your stepping stone has hardened, you should seal it with a tile and grout sealer from a building material store.

Mounting A Mosaic On Clear Adhesive Film

Clear contact paper can be used to temporarily mount a design of mosaic tile, but it really isn’t sticky enough to be as useful as it should be, and it is better to use the clear mosaic mounting tapes (films) that are specifically designed for that purpose. I have used clear contact paper for small mosaics (less than 1 square foot), but even with something that small and simple, there were problems with tiles falling off and moving around when the sheet was pressed into the mortar. Mosaic mounting tapes have strong but removable adhesives. They are available in 6″ widths and 12″ widths, but you can always overlap narrow tape to temporarily mount a mosaic of any width.

Note that clear contact paper is still used in the method explained below, but it only serves to keep the tiles from moving around while you apply the clear mounting tape.


The paper pattern is taped down to the work surface and clear contact paper is taped STICKY SIDE UP over that. The purpose of the contact paper is to keep the tile from moving around after you position them. After all the tile has been placed, the top of the mosaic design is covered in clear mosaic mounting tape, which is much stronger than contact paper.

Instructions for Using Clear Mosaic Mounting Tape

1. Tape or tack your paper mosaic pattern to your work table.

2. Tape or tack clear contact paper UPSIDE DOWN on top your paper mosaic pattern.

3. Position your tile on the pattern, sticking the bottoms of the tile to the sticky contact paper.

4. After all of your tile is in place, cover the top of the mosaic with clear mosaic mounting tape.

5. If your mosaic is larger than a square foot or two, then use a box cutter to cut the mosaic into manageable sections.

Note that sections you cut in step 5 do not have to be squares. Unless you are shipping the sheets to a client for installation by a contractor, there is no need try get them into roughly even squares. Instead, it makes more sense to divide the mosaic in places that make it easiest to line the sheets up when they are permanently mounted in mortar or adhesive.

Advantages of This Method

Using clear mounting tape has several advantages, and they are each significant:

  1. It allows you to work with the tile and the mosaic in progress FACE UP.
  2. The temporarily mounted mosaic is still visible through the clear mounting tape, which can be very important for lining up the sheets when you press them into thinset. A perfectly executed mosaic can be permanently flawed if an installer leaves a slightly extra wide gap between sheets.
  3. There is no mounting mesh involved, and thus the tile can be pressed directly into thinset mortar for maximum life outdoors and in wet locations. Mesh requires an adhesive be used to attach it to the tile, and that is a point of vulnerability, and Achilles heal that moisture could penetrate and delaminate over time.

Expensive Mounting Tape Is Actually Cheap

A 100-foot roll of mounting tape currently sells at our website for either $70.31 or $135.52 depending on whether you get the 6-inch width or the 12-inch width. Now that might be a little steep for a small project at home or maybe even a mosaic for a client that you happen to be installing yourself. But consider the following scenario: You have been commissioned by a high-end hotel or casino to make a 50 square foot mosaic to be installed behind their bar. The mosaic is highly detailed, possibly even photo-realistic, and it is made from several thousand dollars of smalti, and you have spent three or four months making it.

Do you really want to risk having their installer accidentally getting irregular widths between sheets? If you use opaque mosaic mounting paper, then the problem will not be discovered until the mortar has hardened and permanently set.

“Professional Installers”

A word about “professional installers” and other contractors: I have received more than a few emails over the years from high-end architectural jobs in places like NYC and LA where “professional installers” have done things like press sheets of tile PAPER-FIRST (I kid you not) into thinset and similar bonehead goofs. If all your “professional installer” has done is install 4-inch glazed ceramic tile in bathrooms, it doesn’t matter how many years of “professional” experience they have.

If you have to involve a contractor in your mosaic art project, don’t be surprised if you have to talk to a few before you find someone with relevant experience or even basic competence. In my experience, this is true of many aspects of home renovation, but it is particularly true of mosaic. Many contractors claiming to know something of mosaic have actually done only basic tiling using the materials and methods relevant to larger glazed ceramic tile.

Mosaic Backsplash Instructions

There is ample information online about how to go get sheets of tile from a building material store and mount them over your sink and grout them, which is merely basic tiling. This article is more about how to make an original mosaic design and about some basic questions not covered in most of the instructions I saw online.

How-To Questions

Can I tile over drywall?

Yes, for a sink backsplash. For showers and bathtubs, you should replace the drywall with concrete backer board because eventually someone is going to lean against it, and drywall won’t hold the weight. If the drywall has been painted, you will want to sand off the paint or at least scuff it with some coarse-grit sandpaper, something like 80 grit sandpaper.

Do I need to remove linoleum or formica or old tiling first?

Yes, adhesives and thinset aren’t likely to bond to materials designed to be stain resistant, and you don’t want the extra weight and thickness of the old material underneath.

The thickness of the mosaic tile means that my electrical receptacles will be recessed into the wall so far that the covers can’t be attached. How do I fix that?

You would use an electrical box extender (sometimes called and electrical box extension ring). These are available from a building material store such as Lowes or Home Depot. Basically, your electrician removes the receptacle cover, removes the screws that hold the outlets in the electrical box, installs the extender, and then screws the outlets to the extender and replaces the cover. As always, make sure the circuit breaker is turned off and test the outlet to confirm that it is dead before doing the work.

The process is simple and only takes a few minutes, but an electrician can ensure that you don’t accidentally do something that might cause a short over time (such as loosen a wire nut inside the electrical box). I’m a big believer in learning by doing, but electricity can be fairly unforgiving…

Do I need to use thinset?

Unless you are talking about a commercial sink or some other situation where the bottom of the mosaic is frequently standing in water, the answer is no. A high-end brand of white PVA adhesive such as the Weldbond we sell should be more than sufficient if the grout is properly sealed with a tile and grout sealer, which you need to do anyway to prevent staining and mildew.

Of couse, I am talking about attaching small mosaic tile (1″ or less) in an original design, which can be attached one tile at a time directly to the wall, or laid up on fiberglass mesh or temporarily reverse mounted on mosaic mounting paper. Note that our product descriptions for each of these include instructions for how to use them.

If you are mounting sheets or tile from a factory, or sheets that you laid up yourself, then you can spread thinset mortar with a 3/16″ notched trowel and press your sheets into that.

Do I Use Sanded Or Unsanded Grout?

Most of the instructional material I see online says to use unsanded grout to avoid scratching the glass tile, and then other websites say to use the new urethane grouts (which I believe only come with sand) because these are more resistant to mold and don’t have to be sealed.

I’ve never noticed a problem with sanded grout scratching tile, but I don’t use the new popular cheap tiles which are clear glass with enamel color fired on the bottoms. I suppose sanded grout might scratch these because the clear glass is relatively soft and shows scratching more.

Here is what I do know: I regularly get emails from panicky people saying that there are cracks forming in their grout lines as if the grout shrank as it cured, and these people all used unsanded grout. Unless your grout lines are very narrow, the grout needs sand to give it hardness and resistance to impact. Sand in grout is like the gravel in concrete: it isn’t optional if you expect the material to have any strength.

Of course, I am talking about traditional grouts made from portland cement because that is all I use. Maybe the newer epoxy grouts and urethane grouts don’t need sand, but I am unfamiliar. I do know that the working times of epoxy grouts are very short and clean up is more difficult, so you would only use them in situations where you are using ordinary flat tile that could be grouted quickly.

Do I need to seal my mosaic backsplash?

Yes, backsplashes definitely need to be sealed with a tile and grout sealer because they are subjected to occasional splashes, and not just water. There are also food and soap and grease and other materials likely to stain the grout and make it more susceptible to mold and mildew. We use ordinary tile and grout sealers from the building material store. Use multiple applications per the instructions on the bottle a few days after the grout cures. It isn’t complicated or messy. It wipes on and wipes off, and the only thing it does is seal the pores with silicone.

An Inspiring Mosaic Backsplash

Recently artist Karen Whitney emailed me pictures of her bathroom backsplash, which makes use of seashells and other dimensional found objects instead of ordinary flat tile and has a flowing curved border instead of a rectangular stopping point such as a ceiling or cabinet.


Artist Karen Whitney’s bathroom backsplash makes use of a flowing curve border that leaves most of the plaster wall untiled.

What I like most about this mosaic is the story Karen told me about making it, which involved trial and error, improvised methods and patience. This was how I started making mosaics (and most of the other media I have worked in): minimal information, just the basics really, and a willingness to experiment and see what works.

My first mosaic was made with a claw hammer without even the benefit of a tile nipper. That is how deeply my impulse to create had emerged: I had two engineering degrees and had grown up using all sorts of tools on all sorts of home improvement projects, but when my art finally took full control of my life, it did so explosively, and I worked almost by sheer will alone.

I won’t elaborate on the specifics of Karen’s materials and methods because things have a way of getting repeated out of context on the Internet and being cited as authoritative when they are not. Instead, I want to explain how to make such a mosaic using best practices, which ensure durability and can take a lot of stress and labor out of the process.

mosaic backsplash sink detail

The flowing border of Karen Whitney’s mosaic backsplash works well visually because the color of her grout matches the color of her plaster wall. All that being said, a completely contrasting color might have worked well, but I doubt if an in-between color would have. Note how the artist stopped the mosaic at the edges of her electrical covers.

Use Thinset Instead Of Grout

People often email me asking if they can press objects directly into grout instead of using the glue-then-grout method. Yes you could, in a way similar to how tile and objects are pressed into concrete to make a stepping stone, but it makes sense to use thinset mortar instead of grout for several reasons:

  • Thinset is a powdered cement product that looks and handles more or less just like grout.
  • Thinset has strong adhesive properties while grout does not.
  • Thinset is much harder and stronger than grout.

There is one important reason you may prefer to use grout instead of thinset: color. Most building material stores carry 30+ colors of grout but only 2 colors of thinset (gray and white). While thinset can be dyed, it is easier to find a grout that is already the color you want, and then you just add some latex additive to the grout to give it adhesive properties. The latex additive is sold on the same aisle that has concrete, and the package will have manufacturer instructions for how much additive to add to concrete (which would be the same for grout). Keep in mind that when you do this, you are essentially turning the grout into homemade thinset.

Seal Faces Before Use

Grout, thinset and other concrete products can stain any porous materials such as sea shells and unpolished stone. To avoid staining by grout, you can seal these items with a tile and grout sealer, which should be applied to the faces only using a small artist paint brush or a rag dampened with the sealer. Note that you will want to do multiple applications and take care not to get sealer on the bottoms of the objects or any place you want the grout to bond to.

This always seems like a lot of extra work to me, so I usually don’t do it, but that means I have to work extra careful when I mount my tile.

Note that Whitney used polyurethane on her sea shells, which might actually be preferable to a tile and grout sealer, which only seals the pores. The polyurethane is an actual coating, and this might do a better job of filling up tiny crevices where mildew and stains could lodge over time. I am unfamiliar with using polyurethane in this way and generally discourage its use on mosaic art because it might yellow or scratch over time. For seashells used in a shower, it might be a necessary risk to take.

Press Into Thinset Instead Of Glue-Then-Grout

Most mosaic is done like ordinary architectural tiling: tiles are mounted with adhesive or thinset, and then the mosaic is grouted by rubbing wet grout over the face of the mosaic and down into the gaps between the tiles. That is fine for ordinary flat tile, but the glue-then-grout method really doesn’t work when you have dimensional objects such as seashells. Of course it can be done that way in theory, but it takes a lot of rubbing to get the excess grout off something like that, and then there is the issue of staining.

That is why I spread a little bit of thinset mortar at a time using a small trowel or palette knife and press my dimensional objects into the bed of thinset. I don’t come back later and grout. Instead, I apply just enough thinset so that some squeezes up between my objects and fills the gap. It requires some trial and error to learn just how much thinset to apply so that an excessive amount doesn’t squeeze up and stain my objects, and that is why you might want to practice mounting a few objects to a small piece of scrap plywood before beginning your project.

I originally used a Wilton brand cake icing bag to fill in any voids a day or two later. Now I just mount the nipple from the cake icing bag onto a grouting bag because it holds much more material. An artists palette knife is also useful for this type of detail work.

mosaic backsplash tub detail

Whitney’s curving lines of glass gems suggest waves, which adds to the marine theme of the mosaic. Notice how the green gems contrast the warm orange of the shell used as a centerpiece.

Fiberglass Mesh

Whitney laid up her mosaic on fiberglass mesh so that she could work at her table instead of squatting in the bathtub to individually attach each shell. A PVA adhesive such as the Weldbond we sell is best for attaching tile and found objects to mesh. To attach mesh-mounted sheets to the wall, spread mortar using a 3/16-inch notched trowel and press the sheets into it. After the mortar has hardened over night, the mosaic can then be grouted in the conventional way (if using flat tile).

For a found-object mosaic such as Whitney’s, carefully apply small amounts of mortar between the found objects using a palette knife or grouting bag (instead of rubbing grout across the mosaic indiscriminately). This type of detailed concrete work is a labor of love and takes some time, but it is actually enjoyable because you can see the finished product emerging as you work. It is like putting the finishing strokes on a painting.