Mosaic Bases 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.