Chalkzies 0.7mm Extra Fine Point Liquid Chalk Marker &bull; Waterproof &bull; Premium Quality (1-Pack - White) 0.7mm Extra Fine Point Liquid Chalk Marker - Waterproof once dry - Erases with ammonia-based cleaner, i.e. glass cleaner Great for writing small text on chalkboard labels! Water Based - Low Odor - Waterproof - Dust Free - Non-Toxic - Eco Friendly Write slowly with light pressure on a smooth surface. For Use On: Chalkboard Decals, Windows, Plastic, Metal, Ceramics, Glass, Whiteboards and other Non-Porous Surfaces Conforms to ASTM D-4236 & En71. Suitable for Children 3 Years and Above. WARNING: Not For Use On Porous Surfaces, Such As Chalkboard Paint, Painted Wood, Etc. - Please Test On A Small Area First!