8 colors Fluorescent colors glow under black light. 30ml capacity. Water-based paint is opaque. Excellent for use on paper and painted surfaces. 15mm block tip is best for smooth surfaces. A great marker for larger drawing, making signs, and calligraphy. Handmade in the USA. Conforms to ASTM D-4236. Prop 65 compliant. Warning: May cause irritation. Not recommended for children under 6 years of age.