Flexible brush nib graphic design pen perfect for calligraphers and the free hand artist. Pigma brush is capable of drawing very fine lines or broad strokes merely by the pressure applied to the nib. Uses the same pigma ink featured in the Micron series; quick drying, waterproof, fade resistant, will not smear or feather. Permanent on fabric. AP nontoxic, conforms to ASTM D-4236. Acid free.