Chris this is a solution of plexiglass dissolved in acetone usually used in the stabalization of the blanks by wood turners.
Brian here are some photos to some of my other pens with more figure.
Gerry to answer your questions for now here is a link that I posted when I first started using this stuff. http://www.penturners.org/forum/topic.asp?TOPIC_ID=13309
Jim I cant tell the difference at all. I sent one to RTJW on the other site for the pen swap we just had and he loved the finish. He said that it may actually be better than the CA finish. He is the only one with a lot of experience that has seen one yet in person.