Here's a short-lived portable wetplate collodion darkbox I used last weekend in the field at Bill Schwab's northern Michigan APUG get-together. I like the basic design but abandoned this one to an upcoming campfire. I've begun working on the next which will be slightly smaller so it will fit in my cartop carrier. It will also have reversible legs and removable wheels to roll it through the woods, and a drop-tank for sensitizing large wetplates. This prototype was limited to full-plates.
The inside of this box was about 24" deep x 36" wide x 23" high. There was an acrylic sheet for a workspace tabletop inside and a sliding red acrylic window measuring 12" x18" for safelight illumination on the rear panel. The legs slip into slots on the side so the thing could be set up in less than 1 minute. The white material is curtain blackout, totally opaque and cheap but a bit too fragile for this application I'm afraid, so burn, baby, burn. I've acquired some lightweight nylon darkroom cloth from Porter's for the next one which I'm starting to build tonight.
Here I am at O'Neill Lake: