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庐 are also ideal for sketches, drawings, layouts, fashion design and illustration. Store horizontally when not in use.