We're pretty good about answering all questions that pop into the thread, but it's understandable that it might be missed for a bit. I've not made one of the nun's outfits, but I've seen a lot of them, and most are made of a heavy weight, low shine, satin or satin like material that I've seen. This isn't saying that all of them have to made thusly, just the most common material I've seen.
~I've gone to look for myself, if I should return before I get back keep me here!~
Costume list 2009: Finished
17 initially planned :: 15 completed :: 6 moved to next year
Costume list 2010: Started
6 from '09 :: 9 initially planned, now up to 22 total