Have fun with mosaic

In the direct method, the pieces of material you are going to mosaic with, known as tesserae, are directly fixed top-side-up onto a base or substrate and then grouted. In the indirect method, pieces are temporarily fixed top-side-down onto a removable base material.

This is then cast in its final form and the temporary base material is removed to reveal the mosaic, top-side-up. The indirect method is most often used when the finished surface needs to be extremely smooth.

Tesserae are the individual pieces of material you will arrange to form your mosaic. Most people think of those little square pieces of tile seen in early Roman mosaics or in swimming pools. Today the term applies to anything pieced together to form a design.

You can apply a mosaic to nearly any surface, so selecting the base material becomes a matter of the shape you want, how it will be used and where it will be used.

When selecting a base think about the following:

• Is it strong enough to hold the combined weight of tesserae, adhesive and grout?
• Does the base shape have appeal and good proportions?
• The shape should be suited to the size of tesserae you use. Gentle curves are easier, extreme curves can require very small pieces in order to “bend” the tesserae with the curve and have a smooth result.
• Can you find the correct adhesive to adhere the mosaic pieces to the base?

Getting started

• Base surfaces should be clean and dry. When applying a mosaic to surfaces like wood or interior and exterior walls, scoring the surface will add “tooth” and improve the adhesion of your tesserae. Use a sharp knife or similar tool to key the surface.
• Sealing will also benefit surfaces like wood and terracotta. Use a diluted solution of PVA or similar acrylic bonding agent and apply with a brush. It is essential to seal all surfaces of wood bases, and it is also recommended for unglazed ceramic and terracotta.
• All tesserae need to be clean and free of dirt, grease and dust. Wash your materials before breaking them into smaller pieces. Lightly-soiled items can be cleaned with a damp cloth. If the tesserae are attached to a mesh or paper, soak in warm water to remove the backing and glue. Allow all pieces to dry thoroughly. Pebbles need to be soaked overnight and then rinsed until the water runs clear. Allow them several days to dry out.
• Inspiration comes from everywhere. The choice is entirely up to you. You can go from totally abstract to precisely planned. You may want to use or modify an existing pattern. Sketching out a basic cartoon can help you to solidify your idea and to plan for colour and movement. You can draw guidelines directly onto the base for reference. You may want to transfer complex designs onto wood or terracotta bases using carbon paper. Large designs can be transferred section by section.

And finally, do what makes you feel comfortable.