Ive never looked into it, but I know our local 501st has a Revan- so must be in their books somewhere.
Stick with anything cotton based and you will be fine
![Smiley](http://saberforum.com/Smileys/default/smiley.gif)
a bit of texture always adds to the effect, so something like osnaburg or linen and work nicely.
ive made my costume out of homespun cotton. Its heavier, softer and nicer than poplin or broadcloth while remaining cheap and available (for me locally at least) in a very wide range of colours. This isnt approved mind you, im planning to make my membership costume from osnaburg, just as soon as I track some of it down at a decent price lol
![Tongue](http://saberforum.com/Smileys/default/tongue.gif)