JC Crafts Liquid Chalk Markers With Reversible Tip, Huge Variety Pack of 12, Assorted Colors 12 COLOR SET of vibrant artist quality liquid chalk markers. 6mm reversible tips with 8 grams bright and bold neon ink in each marker for long lasting use. Use on any non-porous surface including glass, windows, dry-erase boards, mirrors, signage, metal and more. Easy to use. No messy dust. These liquid chalk markers glide on smoothly and wipe clean with a damp cloth. Great for teachers, restaurants, artists, and more. Not for use on non-porous surfaces. Please test first. Reversible tips for greater creativity. Instantly reverse from chisel to bullet tip, for range of effects.