Chalk Markers Artisan's Effect&reg; Amazing Craft Chalk Markers 4 pack (white) Markers can be used on any non-porous surface. They're excellent for use on glass, mirrors, plastic, metal, glossy & LED boards, whiteboards, chalkboard stickers, chalkboard contact paper, cards and so much more! Note: Markers are not suitable for use on porous surfaces like painted chalkboards and walls. Always test in small areas before us SAFE TO USE - Dust Free for Asthma & Allergy Sufferers. Non-Toxic & Great for Kids Age 3+, Water-Based, No Odor, Xylene Free, Eco friendly. Available in 4 Great Colors White, Blue, Yellow and Red 100% Satisfaction Guaranteed