This uni posca pc-1mr poster marker has water-based pigments which can be blended when wet or overlaid when dry. The have a fine, 0.7 Mm tip which lets you draw thin, detailed lines. The ink produces opaque results that won't fade over time. This marker has a fine, 0.7 Mm nib. You can blend these markers when they are wet or overlay them when they are dry. The pigment ink is fade proof and opaque. The pens have a round, easy to grip barrel.