Pitt Artists' Brush Pen Shades Of Grey - 6 Pen WalletSix shades of grey for preliminary sketches or monochrome plans. These Pitt artist pens have a brush point so that you can give your drawings as much expression as possible, waterproof and very light-fast drawing ink. Extremely fade resistant and waterproof. High quality pigments of unequalled brilliance, ideal for graphic artists, designers, illustrators, fashion and architects. Acid-free.