After you have created your design, what do you output your artwork onto for making your film positives?
The most popular media for making film positives are vellum paper using a laser printer and inkjet film printed with a inkjet printer.
UPDATE: August 14, 2013. The results of our poll are in! After receiving nearly 100 votes from users throughout the world, inkjet film wins out in our survey. Over 57% of respondents use inkjet film, 20% use vellum paper and 23% use both.