According to the Sakura website (www.gellyroll.com):

The Pigma Micron is a fine point drawing and illustration pen that provides the archival quality of Pigma ink. For serious technical and artistic applications, these pens are available in 5 distinctive point sizes and in fourteen colors.

According to animus:

Among the wide range of illustration pens with which I have had experience, Pigma Micron Pens are the best. There are a number of reasons for this.

  • The felt tip is firm enough to maintain comfortable distance from your paper and yet bleeds ink in a smooth, controllable flow. Not so with rapidograph or other bulky refillable pens.
  • Micron pens cost ten times less than other illustration pens of much lower quality. I have yet to understand how the economics of this works. Usually cost translates to quality.
  • The pens last a very long time. I have finished two 24-page comic books with a single set of pens before any one of them gave me problems. This in turn saves you lots of cash, and odds are you need this if you draw comic books.

Do not be fooled by your art and architecture professors when they ask you to use expensive refillables. Micron pens did not exist when they were in school and they are a godsend to poor college students.