Thanks, but not so brilliant. The plastic packing material works much better.
It is hard to describe or photograph, but looks like this:
It holds pins, music wire etc., and does not crumble like cork board.
If you use the cork board, Staples has better quality than the cheap crumbly stuff at Walmart. And if there is no backer, you may need to glue plastic strips to the back to keep the music wire from poking all the way through. None of those problems with the stuff in the photo that can be used over and over again.
Instead of Jack's doll, I use a piece of foam, cut to a coffin shape. The scale I use is 1:6, or 2"=1'. So the foam is 14" long, 3-4" wide, and 2" thick, representing an occupant in a sleeping bag needing 7' length, 1.5-2' width, and 1' height to be comfortable. The foam can also be bent up to see if your head is likely to hit the canopy when sitting up - always a consideration with single wall tents that are often wet with condensation on the inside.