It's impossible to see the pencil marks in this picture, but I used a 12X18 piece of paper as a template to cut the hole.
(Pardon the mess in these photos. We live here.)
Secundus chose pink for her curtain color. We just used construction paper, but I will have to replace it with fabric soon for more durability. I really like how the accordion-folded paper along the top looks, though.
We added a fabric curtain in the back to give her puppet shows a nice backdrop.
Why, yes, I did use staples to make a casing for the string. I just punched a hole on each side of the board to tie the string to. So if she doesn't want a background, the curtain can be pushed to one side.
Folds nice and (almost completely) flat.
I predict we'll be getting a lot of use out of this this year, especially as we learn and retell nursery rhymes and fairytales for our literature unit.