Originally Posted by G3:
I Which thickness should I buy or do you have a better recommendation?
It's all a personal preference, what works best for installation, what looks best when done.
For me, a thicker acetate is preferred. The thinner stocks (.003/.005) are too flimsy to work with, sometimes end up a bit 'wrinkled' or wavy on larger windows/panes for my liking.
Evergreen makes a clear styrene in .010 (9006) and .015 (9007) thickness. Either of those is preferable to moi. Unfortunately, Evergreen has been going through some change of ownership, or some such disruption, and the clear sheets (esp. 9007) have been out-of-stock for a bit. They'll be back, though. Of course, there are other purveyors of sheet styrene/acetate, too.
FWIW, always...
KD