Chalk Markers by Wonder Chalk - Liquid Chalk Paint Pens in 10 Bright Colors, Wet Erase, Odor Free, Non-Toxic Water-based Ink, 6mm Reversible Tip for Fine or Thick Lines on Chalkboards & Non-porous Surfaces Be Creative with these VIBRANT Chalk Markers that are perfect for Non-porous Chalkboards & Much More Works Great on Chalkboard Contact Paper, Chalk Labels, Bistro Boards, Glass, Mirrors, Whiteboards 6mm Reversible Tip Draws Thick or Thin, Crisp, Smudge-proof Lines Using Premium Quality Chalk Ink Paint Dust Free for Asthma & Allergy Sufferers; Non-Toxic & Great for Kids Age 3+, Water-Based, No Odor Wipes off Easily with Water ON NON-POROUS SURFACESIMPORTANTALWAYS TEST SMALL AREA FIRST