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.
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 with the sticky side facing up.
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:
- It allows you to work with the tile and the mosaic in progress FACE UP.
- 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.
- 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.
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.