Micron Pigma Pens contain pure pigment in a felt tip! Waterproof and chemical proof. They are excellent for drawing, graphics, documents, outlining and lettering work. For best results spray with a matte varnish after using so that the ink won't smear as it would if varnish was brushed on. Each pen in this set is .05 tip. Colours include: Black, Red, Blue, Green, Brown and Purple. Note: When not using these pens ensure that the cap is on tight. These pens have a felt tip so remember not to press too hard or the tip may bend causing ink flow to stop.