I made one out of 3 pieces of 1/2" electrical conduit, bent 90* radius' with my conduit bender, then used connectors to form a U-shaped curtain rod. Dimensions were roughly 7'x9'. I attached it to the back of my shop overhead door rail with conduit connectors, and used 1/4" rope to support the front of the 'U',. Bought a 10'x25' heavy mil plastic tarp from Lowes, and folded over the top 6", installed brass eyelets every 12". Then used metal shower curtain snap-rings to hang it from the curtain rod. All that was left to do was cover the back of the door and floor with a disposable plastic paint tarp, and put a box fan exhausting outside (by raising the door 10" or so when needed).
I put a metal table in the "booth" to paint the parts, and moved them to a seperate drying table outside the booth, when they were ready to handle. It worked out so well, I will certainly use it again. Meanwhile, it is stored in a cabinet, out of the way.