Cut glass wall tiles using a glass scoring tool, wet saw or glass tile nippers. The appropriate tool depends largely on the size of the tile.
For glass tiles that are 2 inches or smaller, use glass tile nippers. Start by holding the tile with one hand and the tile nippers with the other hand. With the nippers positioned where you want to cut, squeeze the nippers until the tile splits. If the entire line is not cut, repeat the process until it is.
If the glass tile is 4 millimeters thick or thinner and does not have a color painted on the back, the score and snap method is used. Place the tile flat on the table, and score the glass with a glass scoring tool starting from the furthest edge of the tile to the closest. Turn the tile around, and rest it on a thin wire that connects with the scored mark. Put pressure on both side of the tile to snap it down the scored line.
Use a wet saw to cut all other glass tiles. Place a tile on the tray of the wet saw with the back facing up, or if it has a colored back, place the other side face-up. With the tile positioned in front of the spinning saw blade, push the tile carefully through the blade until the whole tile is cut.