When you drill or cut glass tiles there is often a risk of excessively damaging the paint which is on the underside of the tile. If the paint is removed by the tool you are using, the damage will be visible through the glass when the tile is laid.

 

Here’s a video that shows you how to drill glass tiles and glass mosaic quickly and avoid damage to the paint. The ‘trick’ consists in starting the drilling process on the painted side of the tile and then turning the tile onto the upper side to finish it. With this technique you get a much cleaner hole while preserving the paint almost totally intact. It might also be useful to use a small piece of drilled wood as a template/guide to keep the diamond drilling tool in the right position on both sides. Obviously it is necessary to use a diamond drilling tool designed for glass, such as the Montolit FAJ core-bits which can be used, both, with or without water.