Developed with professional hand lettering artists, this set is ideal for creative lettering and letter art! The odor-free pigmented India ink is lightfast, waterproof, permanent, acid-free and pH Neutral. The brush pens can create lines from 1 to 5mm. The superfine pens in 0.3mm are great for adding detail. The Pitt Artist Pens® are also ideal for sketches, drawings, layouts, fashion design and illustration. Store horizontally when not in use.