(Also see Glass Tile)
Some glass tiles are quite sensitive to scratching, such as glass tiles that are made of soft glass and glass tiles that have an iridescent finish. These types of delicate glass tiles should only be grouted with an unsanded grout like MAPEI’s Keracolor U. Adding MAPEI’s UltraCare Grout Maximizer to MAPEI’s Keracolor U will help to reduce the porosity of the grout and help to keep the grout clean.