Originally Posted by Angelnorth
This is a great idea and there's probably a simpler way than the one Cobby describes. The acetate doesn't actually need to be the shape of the bell jar for this so you can do away with the need to hand cut templates etc - just cut the jar from carstock and then put a piece of acetate behind the aperture you just created. The acetate can be rectangular like the cardstock piece and you can use adhesive anywhere on the cardstock without it showing.
Angelnorth....you are a genius! Why didn't I think of that. SOOOOO much easier than what I described. ( slapping myself upside the head now...).