A How-To Guide to Mosaic
Learn How to Create Your Own Mosaic Art
Mosaics are colorful. Surprising. Emotional. Evocative.
In addition to visual appeal, the mosaic piece must also be appealing to your touch. Each and every bit of tesserae is smoothed or ground in some way: no sharp edges! I use a handheld carborundum stone, or sometimes I tumble the stained glass in a rock tumbler. The picture frame shown below is made up of several different levels of tesserae, but when you run your hand over it, it is completely smooth.
If the mosaic is a horizontal surface, such as a table or stepping stone, I want you to be able to set your glass down without it wobbling and I want you to walk over the mosaic without tripping or cutting your bare feet. So my picture frames and wall hangings might have lots of different levels of tesserae, but my table tops and stepping stones will be flat.
I want my work to last. The substrate must be suitable for the mosaic. The right adhesive must be used. I've learned a lot by trial-and-error and done plenty of research on the subject of indoor and outdoor mosaics.
How to Begin Planning Your Design
I recommend that you start with a flat piece, such as a picture frame, and then move on to three-dimensional objects. After you decide on your design or imagery and the materials, you will then think about the background of your design. The technique of the way you will lay your background tile is called "opus." This means the way you surround your imagery with a more neutral tile.
- Opus tessellatum means that you surround your image(s) with one or two bands of background tile.
- Opus vermiculatum is where the tile resembles curved lines and gives a sense of movement to the background.
- Opus palladianum, my favorite, is random, haphazard, and asymmetrical—and is actually quite challenging, as it requires a lot of vision and hard work to fit the pieces together in a pleasing manner.
- Andamento is where the tiles flow in directions, giving a sense of movement to the background as well as rhythm and flow.
Mosaic Supplies and Materials
The basic materials and supplies you'll need for a mosaic project are a substrate, some tesserae, adhesive, grout, sealant, and various tools.
How to Choose a Substrate
- For indoor projects, use wood, terracotta, glass, etc.—almost anything except flexible plastic. The substrate must be rigid. If it flexes, the grout will crack.
- For outdoors, do NOT use wood. Wood will eventually warp no matter how well it is sealed. It swells, expands, and contracts. Use hardibacker, wedi board, cement backer board, glass, Plexiglass, or concrete instead. Some terracotta will hold up well for years, and other terracotta will not; this might be due to different clays and firing methods. MDF is porous so if you use it, seal it very well. I prefer not to use this substrate.
How to Choose Tesserae
Ceramic tile, vitreous glass tile, stained glass, smalti, broken china and pottery, glass beads, shells, pebbles, and jewelry are good options. Avoid wooden beads and organic beads (such as those made from beans or pods) UNLESS they are well sealed.
Decide on Colors and Theme: Select your tesserae with those guidelines in mind. The picture frame I show here was first painted a bright orange. The stained glass I used is also orange, but it is semi-transparent, so the orange substrate intensifies the color. I like using a mixture of large and small pieces; I think it adds interest. If you look at a color wheel, you will see that orange and blue complement each other; they are opposite on the color wheel. The blues are placed in a random fashion, yet the placement is calculated. A piece that is located high up on the left is balanced by a similar piece that is low down on the right, and so forth. A good way to check your design is to stand back ever so often and take a critical look.
Consider Texture and Variety: I used a few glass globs (flattened marbles) because I think they add something to a mosaic, but I keep them to a minimum. There are only five on this frame. I used flat round tiles, a total of seven. Odd numbers are more interesting than even. The challenge here is to use only odd amounts of tesserae and yet produce a balanced and pleasing piece. Please note the use of dichroic glass. It is fascinating and full of fire, like an opal. I love dichroic glass, and again, I use it sparingly, because 1) too much is over-powering, and 2) it is extremely expensive.
Where Can You Find Mosaic Tesserae?
Stained glass can be purchased in sheets from stained glass stores, hobby shops, and online. Did you know that most stained glass shops keep bins of scrap glass, which is very economical and perfect for mosaicing? Scrap glass is sold on eBay, too. Also, plates and old bits of costume jewelry can be found at thrift shops and garage sales.
A local tile shop here has a "tile graveyard" outside where you can pick through and take what you need for a small amount of money. I have been told that some tile showrooms just throw away their displays and samples when they change out their displays.
And finally, once you get involved in mosaics, you will want to join discussion boards online. One lady in Michigan posted photos of some old plates that she found for practically nothing at a garage sale. They were my favorite much-sought-after discontinued pattern. We worked out a trade. That same discussion group has two or three exchanges each year where names are drawn and large, USPS flat-rate priority mail boxes full of goodies are exchanged.
Use Wheeled Nippers to Make Tesserae From Plates or Tiles
Many people have the notion that, if you use dinner plates or tiles for tesserae, you should just put them in a towel and smash them with a hammer. I prefer to use a tool called wheeled nippers and cut the pieces in the shape that will work best for me. I don't recommend smashing plates with a hammer.
How to Choose Adhesives
- For indoor projects, use Weldbond water-based glue (except mirror tiles) or MAC glue. Note: Do not use Weldbond for outdoor projects. When wet, Weldbond may revert to its liquid state and release the tesserae.
- For outdoor projects, use Mapei brand Ultra Flex 2 polymer modified mortar (this is a thinset that can be used as an adhesive and as a grout). I have also used the GE Silicone II on outdoor projects and so far it is holding up well.
- For mirror tiles, I use GE Silicone II Kitchen and Bath clear sealant. High-solvent adhesives can damage the mirror backing. I recently read that the pros almost exclusively use "Mirror Mastic." It seals and protects the mirror backing. You need a calking gun for the tube. Seal the tip well between use. It works well, but is messy (sticky). I have not used it myself.
- For glass on glass, use MAC Glue, available only online. One place that carries it is Maryland Mosaics.
How to Choose Grout
Use olyblend sanded grout mixed with water, or other sanded grout that does not contain a polyblend mixed with Acrylic Mortar Admix instead of water.
A Safety Note: I do not recommend unsanded grout or premixed grout. Do NOT breathe in the powdered grout—it can damage your lungs!
How to Choose Sealants
- For indoor projects, use Aqua Mix Grout Sealer or DuPont Grout Sealer. Brush on, polish off the tesserae.
- For outdoor projects, use Aqua Mix UltraSeal Premium Stone & Tile Sealer or DuPont Grout Sealer. Spray on, polish off the tesserae.
- Tile nippers. The best are the wheeled Leponitt nippers. Toyo pistol grip glass cutters are good for cutting straight lines in stained glass.
- Small wire cutters for removing the pins from the backs of jewelry.
- Carborundum stone. This may be called a kitchen sharpener. Look for one with a handle. Use this to take the sharp edges off of glass or broken plates.
- Rectangular sponges to wipe the grout off the tesserae.
- Old terrycloth rags, craft sticks, and plastic bins for mixing grout and for water.
- Blue painter’s tape.
A ring saw or other wet tile saw is nice to have, as is a glass grinder, but these tools are not must-haves.
I recently learned how to mark a pattern on stained glass (or tile) that I am cutting with my Taurus 3 ring saw (a wet saw made especially for stained glass work). I am pleased to pass on a solution to your pattern washing off as you cut. DecoColor Opaque Paint Markers come in every color and in broad line and fine line, and the lines will stand up to the water from the ring saw. They're the kind of marker that you press the tip to a piece of paper to get the paint flowing.
To remove the marks from the glass, alcohol won't work but I can scrape it off with an old dull-bladed knife, or I can easily sand it off with one swipe of a 3M fine sanding pad.
Basic Steps to Make a Mosaic
1. Glue on tesserae. Wait 24 hours.
2. Grout. Clean tesserae. Wait 24 hours.
3. Seal. Clean tesserae.
4. Paint grout (optional).
Step 1: Glue the Tesserae
There are three different gluing methods you can try: the direct method, the indirect method, and the mesh method.
Glue tesserae directly onto the substrate. Tesserae can also be glued to mesh and then transported elsewhere and affixed to a wall or a fireplace surround, for example.
Lay tesserae upside down in a mold coated with Vaseline or mold release, and pour cement, as for a stepping stone, or glue tesserae upside down onto brown Kraft paper. The indirect method is usually used when a smooth surface is required, or when mosaics are made in a studio and then transported elsewhere for installation. The tesserae MUST be flat.
You can mosaic onto mesh, and then peel the mosaic up and transport it elsewhere for installation.
- First, select a large flat surface such as an old cutting board.
- Cover it with a cellophane wrap-type substance such as a large baggie, trimmed and opened up so that it is one flat layer.
- Tape the baggie to the cutting board all the way around the edges.
- Lay down a piece of mesh.
- Now, mosaic onto the mesh, using a Weldbond-type glue sparingly. You want to use just enough glue to attach the tesserae to the mesh, but still leave gaps for later gluing.
- Wait until the glue is set up and then slowly and carefully peel the mosaic up off of the cellophane-covered cutting board.
- Trim any excess mesh. Lay flat and upside-down to dry.
Here is an example of using this method: I was commissioned to mosaic a large fireplace surround. I mosaiced many 12-inch squares onto mesh, dried thoroughly, and then stacked them up and transported them to the job site. I glued them to the surface, held and pressed for a few minutes, and then used a strip of blue painter's tape to attach them temporarily. Every few minutes I would go back and press until they were firmly attached.
Tip: When working with a random pattern, leave the edges of each mesh square irregular, and install them an inch or so apart. Then fill in the gaps. This saves hours of work and especially saves time and effort when working on a vertical surface. Also, I just read about a front mount adhesive film that sounds interesting and comes highly recommended. I intend to order some here and try it out.
Step 2: Grout
After gluing, wait 24 hours and then grout.
- Selecting a grout color is extremely important. My favorite color is a soft pale brown. Another favorite is black. My least favorite is white. Carefully shake some dry grout onto your piece and into the grout lines to see if the color works for you.
- Mix the grout with water or admix or a mixture of both. Mix in a disposable container. Do NOT breathe in the grout dust. Mix to a consistency of peanut butter.
- Wait up to ten minutes (this is called slaking) and then spread with a tool or popsicle stick, or with your gloved hand. Make sure the grout fills in every nook and cranny.
Note: Never wash any grout down your drains. It will ruin your plumbing. I grout outdoors when possible, but when I do grout indoors, I go outside to dump the water that I dip my sponges in.
I recently tried this method and it works! For small applications, such as a picture frame, mix your grout in a sandwich bag. Add the dry grout first, then water, then squish it around to mix up, and when you like the consistency, zip the baggie closed and cut a small hole in a bottom corner. Squeeze the grout out as if you were decorating a cake. No muss no fuss!
How to Remove the Excess Grout and Clean Up
- Wait a moment or two and then gently begin to remove the grout from the tesserae. At first, use your gloved fingers, and then a dry paper towel.
- After removing the excess, gently pass over the mosaic with a damp sponge (not a dripping wet sponge). Your goal is to remove the grout from the surface of the tesserae but you do not want to dish out the grout lines; you want them to remain smooth and level with the edges of the tesserae. At this point, you can pat the grout with a sponge or your finger and you can smooth a problem area with a wet makeup brush.
- Continue to wipe with a damp sponge; rinse your sponges in a bucket of water between each use. Wash your sponges out thoroughly when you are through with this process. Throw the water away outside and refill your bucket with fresh water until your sponges are completely rinsed out.
- Allow the grout to firm up (about 30 minutes) and then carefully wipe the haze off the tesserae. When you are certain that the grout won’t be disturbed, you can firmly polish the mosaic with a wet washcloth, wrung out well.
What to Do If Your Grout Fails
If too much water is used to mix the grout, it might fail because it's weak. Another possibility is that the dry ingredients separated and settled within the bag and the proper proportions weren't mixed. The way to make sure this doesn't happen is to mix the entire bag of grout while it's dry before you scoop some out to mix with water. I know this is not a pleasant thing to do. I buy the smaller bags of grout so it's less trouble, and then you can dump the entire bag into a bucket, stir it up (dry), and then scoop out what you need for your mixture. I do this outside. Take care not to breathe it.
Step 3: Seal the Piece
Allow to sit undisturbed for 24 hours (or longer), then seal. The sealer has the consistency of water. Apply all over the piece, making sure that the edges are well sealed. Immediately polish the sealer off the tesserae.
Step 4: Paint the Grout (Optional)
I often paint the grout. On the picture frame pictured above, I used copper metallic. I seal the grout first, then paint with acrylic paints. I use a natural sea sponge (also called a silk sponge or a cosmetic sponge) to apply the paint:
- Wet the sponge first and squeeze dry.
- Squirt out some paint into a lid, then dab the sponge in the paint.
- Randomly sponge all over the mosaic.
- Wipe off the tesserae with a damp cloth.
I like to use more than one color of paint. Just remember to wash your sponge often because the acrylic paint dries quickly. If you want a shiny finish, you can shellack the entire piece. I use Liquitex Gloss Varnish. I buy both the varnish and the acrylic paint at Michael's or Hobby Lobby.
Mosaic art: Have fun with it, beautify your surroundings, inspire others, leave something beautiful behind for future generations to enjoy, recycle, make friends with mosaic artists all over the world, check out groups on Facebook . . . it's all good.
Please check out my blog; I talk about projects I've done and include pictures. Some of my projects are the stair risers in my home, a glass-on-glass totem, and several guitars.
Questions & Answers
© 2010 Silva Hayes