I picked up a 10'x20' backdrop cheap from a studio that was closing. It's been a great thing to have, even if it does look like overgrown camouflage. So anyways, had a shoot a couple weeks back at a warehouse. Lots of good stuff, but the floor was dirtier than anyone expected. I had 4 backdrops out, a white polyester cloth about 6'x 12', a few dark black pieces about 8' square, a 9x12 canvas and my 10x20. They all got extremely dirty, a combination of old floor dirt and what is probably machine oil, as the place was a factory at one point. I was very happy with the shooting results, but not very happy at all with the condition of the backdrops.
I wasn't too worried about the white and black ones. The dirt was barely visible on the black one, and the white one was highly replaceable. Even so, I threw them in the washing machine and was pleasantly surprised when both came out mostly clean. I sent the white one through a second time as some dirt got trapped in the twists, but both came through very clean. This was encouraging.
Unfortunately, the washer is not big enough for the canvas or 10x20. And I wasn't sure how well the 10x20 would survive the washer anyhow. So off to the bathtub. The canvas one went in first, and with a bit of Tide and some hand agitation in cold water and it came clean much easier than I expected. Had to lay it out on the sunporch to dry, but it seems to be no worse for the wear. I started this morning with the same process on the 10x20, and it seems to be ok. I had to do two wash sessions, and even then the rinse water is not exactly clear. It weighs a ton when it's wet. Now I just have to let it drip/drain for a while, then I'll spread it out to dry as well and we'll see how it looks.
Of course, everything is wronkled. I'm being told that a steamer is the way to go, but I haven't got one and somehow spending $50 on a steamer for a $40 backdrop just seems wrong. Maybe I can find a used one somewhere, or bribe someone with a masochistic streak into ironing it....