Ink dries acid free Permanent and non-toxic Refillable and Replaceable nibs available Medium Broad Chisel tip and Super Brush Nib tip Sketch available in 358 Colors with Guaranteed Color Consistency Copic Sketch markers are designed for creative people! Known throughout the world for their high quality. Popular with comic and animation artists. Refillable, Inks with guaranteed color consistency. The double-ended sketch marker has a medium broad nib and a super brush nib. Excellent for all forms of illustration, design, and fine art. Oval shaped barrel, 358 colors available, with 3 nib options. One various ink can fill this marker about 12 times. Compatible with Copic Airbrush system.