Porcelain Mosaic Tile 20mm (3/4 inch) is the unglazed Lyric brand, which has solid color throughout. Porcelain is much harder and more durable than ordinary ceramic tile, and it is impervious to liquids and frost resistant. Lyric is suitable for floor mosaics indoor and out. Most colors are mounted on removable paper, but a few are sold loose by the half pound. MAKE SURE YOU ORDER ENOUGH FOR YOUR PROJECT NOW. DO NOT ASSUME YOU CAN ORDER MORE LATER BECAUSE THE FACTORY HAS NOT BEEN VERY SLOW TO RESTOCK MOST COLORS.