Mosaic tile is available as a commercial or handmade product. Commercial tiles are generally standard in size, shape and thickness, and are mounted to mesh sheets for easier installation. Handmade tiles are often of different sizes, shapes and thicknesses, and they can be shaped on site using small hand tools. A mosaic artist working off-site can mount his design on mesh so it can be installed like its commercial counterpart.
Cut porcelain or tile mosaic tiles with a porcelain or ceramic tile nipper. The nipper is a handheld tool with opposing nips (also called chisels, or teeth). The porcelain nipper is designed for the harder tile, either type will usually work.
Place the tile between the teeth and compress the handles together. The tile will crack where the nips grab.
Cut glass mosaic tiles with mosaic wheel cutters. This handheld tool is similar to a nipper, except that the opposing cutting edges are wheels.
Place the glass tile between the cutting wheels. Position the edge of the wheel along the line you wish to cut. Compress the handles and pull the cutter firmly and quickly. This will create a clean cut. A slow movement might crush the glass and ruin your cut.
Cut thin stone tiles with a hardie and a mallet. A hardie is a type of blunt chisel that is positioned along the cut line while the mallet strikes the end. It may be necessary to cover or wrap your tile in a towel to protect its finish when you strike.