2-3 mm medium point tip Tip Water-based Acrylic Black Marker. Works on almost surface. The water based paint Black markers are great for rock painting, stone, Tire marker, ceramic, wood stencils, metal pottery, graffiti, comic books coloring, chalkboards, terracotta pots, polymer clay, porcelain, leather plastic, fabric creations, canvas, clothing, shoes, glass, mirrors, paper, chalkboard craft supplies terra-cotta, polymer clay, custom mugs and other personalized gifts. WHY CHOOSE OUR PAINT MARKER. 1.non-toxic and acid free. But don't swallow it and No food contact. 2.High quality ink is Chemically Stable, Waterproof ,and Fade Resistant -- making it easy for you to seize your inner creativity. 3.Dries quickly, no worried about messing up while painting. 4.Safe Ink, no leak, no harmful chemicals, safety for kids and adults.