I am working on a performance piece that takes places in an 8'x8' cube. The cube is composed of a wooden frame with painted muslin drops filling in the walls and the ceiling. The painted drops need to change throughout the performance and to disappear entirely at certain points.

I am posting this to find out if anyone has any ideas on how to rig a spring-loaded roll drop. It should essentially function like portable projection screens do - a dowel at the bottom of the drop will be pulled to unfurl the drop and then hook onto the bottom of the frame, keeping the drop open. The top of the drop would be attached to another dowel that is spring-loaded so as to maintain constant torque, pulling the drop tight. When the bottom of the drop is unhooked, the top dowel will roll the drop back onto itself.

I've been mulling over this for while, so any ideas to achieve this in a relatively economic (both financially and spacially) way would be greatly appreciated!

Thanks, but i've already read that article and all it says about spring-loaded rolls is that their rig is NOT one. 

thank you so much, David.
I had dismissed this idea earlier, assuming that blinds would be too expensive, that they wouldn't take paint well, and that the locking feature you mentioned would get in the way. but i did some tests today and found that 6'x6.5' blinds are only $30, that the vinyl actually takes paint really well and will roll up easily, and that the locking mechanism can be removed with a leatherman and some willpower. I'll be doing a full-scale test tomorrow to make sure that this is the right solution, but thanks for making me revisit this idea!