Grout is a tacky adhesive substance used to fill the spaces between tiles and attach sheets of tile to the surfaces that they are installed on. Made from a combination of cement, sand, and water, grout is typically sold as a dry mix that must be blended with water before its use in the tile installation process. Grout can be combined with chemicals (admix) to make it stronger, mold resistant, or more flexible, a necessary step when installing tile in high-moisture or high-traffic areas. Proper grouting will strengthen the tiled surface and enhance the appearance of the tiles. Latex-modified grout should be used when installing glass tiles. The addition of this flexible material (latex) ensures that the grout holds tight to the non-absorbent glass tiles as it dries, without putting excess stress on them or the work surface. Glass tile grouts are available from Susan Jablon Mosaics in a wide variety of complementary colors. Since your choice of grout color will be a significant factor in the final appearance of the tiling project, choosing the right one is a critical stage in the design process. Remember that grout is an accent material that should complement the beauty of your tiles, not compete with them for attention.