Faber Castell - 6 Pitt Artist Pens - Shades Of Blue . These Faber-Castell PITT Artist Pens have brush tips which are capable of drawing lines of varying width. This makes them more flexible than normal bullet-tip markers. Large areas can be covered quickly by holding the pen at a fine angle to the paper and pressing firmly, while fine detail can be sketched if the pen is held upright and used lightly.