Tag Archives: tutorial

Cutting Vitreous Glass Mosaic Tile diagonally to make triangles.

How to Cut Diagonal Triangles from Vitreous Glass Tile

Many people report having trouble cutting vitreous glass mosaic tile reliably because of the embossed patterns on the back sides, which can interfere with the blades of the mosaic glass cutter, but if you take simple steps to minimize interference and rotation, it can be done.

What I mean by interference is when the blade slips down into a valley between two ridges instead of staying positioned in the desired line of the cut. Continue reading

stained glass shards in buckets

How to Make a Stepping Stone with Scrap Glass

If you work with stained glass over time you can end up with buckets full of scrap. When the pieces start getting too small and irregular, or if there’s just too much of it, you can used them in a stepping stone. This tutorial demonstrates how to make a stepping stone with an abstract pattern. You can also use tiles instead of stained glass scraps.

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"Element" mosaic art

How to Hang Mosaic Art with French Cleat Wall Mounts

Small mosaic plaques can be mounted on a wall with a the same type of hangers and wires used for paintings provided the nail on which it hangs is mounted in a stud inside the wall, and even then redundant wires and fasteners are recommended. However, larger mosaics need more robust mounting hardware. The “french cleat” is a type of wall mounting that can be used to securely affix heavy mirrors, cabinets or artwork to a wall. In addition to its strength, the french cleat also allows mosaic art to be mounted flush against the wall and makes leveling it easy.

If you built a frame on the back of your mosaic as described in this tutorial, then french cleat molding is a good hanging option.

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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.

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.

How To Mosaic Bar Countertops

This article is about how to incorporate mosaic art into the design of your tiled bar top and is less about the basics of how you mount the plywood, cut a hole for the sink, etc. If you need that type of basic construction information, there is an article on HGTV’s website about how to tile a countertop.

However, I noticed that the HGTV article didn’t specify the thickness of the concrete backer board to use. For a floor, you must use 1/2 inch concrete backer board, but for a countertop, you can use 1/4 inch and probably should because it makes it easier to cut a whole for a sink with a jigsaw. You can’t cut plywood and concrete board at the same time because the blade gets dull too rapidly from the concrete, and then it rips the plywood instead of cutting it cleanly.  Make sure you have holes in your plywood before laminating.

Back to mosaic art and how to incorporate it into tiled countertops:

Recently a customer emailed me with some photos of a bar top she had mosaiced for her home, and I thought they were worth showing off for several reasons. Not only were the execution and color choices well done, but the design complemented the color scheme and decor of the room as a whole, yet still managed to have its own merits as mosaic art and not be mere tiling.


Mosaic countertops are easily replaced if the next home owner doesn’t care for the design. Unlike many forms of home renovation, these projects are relatively low-cost yet have maximum visibility and design impact. Photo courtesy of artist Charlotte Ward.

I think it is important to promote successful examples of architectural art because contemporary tastes have tended to converge on “basic black” and Bauhaus clean functionality in a monolithic way, especially when home remodeling is concerned. I certainly understand the reasons why: who wants to spend money to make their home less sellable? Who wants to customize their home in a way that most potential buyers might find unattractive?

Even if we have confidence in our own artistic and design skills, those of us who have lived in tight real estate markets have seen too many houses in “up and coming” neighborhoods where the previous owner may have had little money, but apparently had even less sense and spent $15 to $20,000 to add a room or porch that made no design sense at all or cut windows and doors where they made no sense or bricked them up with equal indifference. After being forced to consider such houses merely because they were the only thing on the market within budget, no rational person wants to even risk the possibility of spending money in a way that makes the largest investment of their life lose value.

And so we err on the side of caution and dismiss any individualistic ideas about home renovation and go for simple clean designs that lean toward the generic.

But that sort of thinking is why 9 billion houses have black granite countertops, and that is why those same black granite countertops will one day be the most despised, dated feature of those houses. If you doubt this, consider how many landfills full of real heart-of-pine paneling that you have seen ripped out of houses on HGTV home renovation shows. The wood paneling is rich-colored natural material (just as the granite countertops are rich-colored natural material). We just don’t like it anymore because it is so indicative of decades past because it was so widely used at the time.

The good news is that things like mosaic countertops and mosaic fireplace surrounds are easily replaced if the next owner or potential owner doesn’t care for the design. Unlike many forms of home renovation, these projects are relatively low-cost yet have maximum visibility and design impact. In short, mosaic countertops may be one of the few personalized home renovation projects you can pursue without jeopardizing the “curb appeal” of your house.


Brown copper and vegetable green are natural color compliments. This color combination also has connotations of old brass with a green patina, so there is an “antique” feel to the color scheme, which is very appropriate for a bar used for entertaining. Photo courtesy of artist Charlotte Ward.

Inserts In Regular Tiling

Note that you don’t have to mosaic the entire bar. The side edges can be regular bullnose ceramic tile, and mosaic art can be an insert in the middle of the regular tiling. All you would need to do is leave an un-tiled space in the middle of the bar (or instruct the building contractor to do so). Then you could put your own mosaic design in that space. Glass mosaic tile (typically ~1/8″ thick) is slightly thinner than ceramic tile (typically 1/4″ or 3/8″), and so you may need to build up the un-tiled space slightly with mortar before you mosaic it, but that isn’t difficult.