Pentel 10-15mm Chisel Tip Wet Erase Chalk Marker 12pkPental Liquid Chalk Wet Wipe Glass, Chalkboard Marker Jumbo Tip BLACK Pental Liquid Chalk Makers are ideal for writing on glossy surfaces such as glass, mirrors, whiteboards and ceramics where the ink can easily be Wet erased for re use. For permanent results the markers can also be used on chalkboards making them perfect for use in cafes and retail environments or schools and offices.