It's been a while since I came across this technique, so I'm not sure where I first heard about it. Anyways, the idea is to take a piece of cloth and paint or spray bleach onto it, to selectively lighten the fabric. This is so fun and simple that I am having a bleach party next weekend; we will throw bleach EVERYWHERE and create MASSIVE DESTRUCTION. (Perhaps I EXAGGERATE slightly.) It will be MARVELOUS!
I have lots of somewhat-ill-fitting solid-color tank tops from thrift shops, so it was easy to pick out some fabric to play with. Natural fibers, of course, work best as they will absorb the bleach. However, the bleach will weaken it, so go easy. I diluted the bleach a little, so I'd have more time to draw before I rinsed and the designs wouldn't appear gradiented. A while back David and I liberated some sheets of plastic from the Art Museum dumpster, and those make excellent mounts: they provide a stable surface and prevent the bleach from leaching through to the other side.
I set up some newspapers and one tub of bleach, one of water. I needed way less bleach -- you really don't use much at all -- though most of that is water, later cast out because I wanted the solution more concentrated. I didn't end up using the gloves either; I did 5 shirts, and my hands are fine. Those brushes have nylon bristles, which held up fine to the bleach, and they will be dedicated for this specific use.
Shirt on long plastic board, which I could rest on my legs and lean against the table as a sort of easel. This was my experimental shirt: I was still getting the concentration right, so there's kind of a crappy drawing of birds and dinosaurs on it now. My drawing technique also improved dramatically over the hour or so it took to do five of these.
Some crappy nature tableau.
Attempt to recreate the Reclamation logo from Templar, AZ (plus identifiers for Soviet 12). All-cotton shirt; brown dye -> pink. Meh.
About 5% cotton tank: took several applications, but that looks kind of cool anyway.
Mandelbrot set tank. 95% cotton, black dye -> pinkish orange. Came out quite nicely, and got a lot of comments. Etsy?
Balloons! Balloons balloons balloons. There's a UFO on the shoulder. All cotton; very fast color change. Kind of pinkish.
A reference to the excellent VURT, by Jeff Noon. Greenish fabric -> yellow.
After painting each shirt, I ran it under a stream of warm water, which worked fine to get the bleach out. At the end, I ran everything through the washer with no detergent (I'm not sure this matters) and the dryer. The lighting was poor by that time, and so result pics will have to wait until this afternoon.
• Colors: Brown dyes and some blacks tend to go pinkish, while greens come out more yellow. Fabric with a low natural fiber content will come out with a fainter design, but it will match the overall color fairly closely. A black 5% cotton shirt bleached to a subtle medium grey, though it took a few applications for the design to really show up.
• Brushes: Small tips offer great control, but they also hold less bleach, which means less of a feathering problem. Bleach mostly stays where it's put. I've heard of using spray bottles, which might be fun to try, but I don't have the patience/control to cut out stencils.
• Fabric: Ribbed material will leave dark lines in the design, unless you want to bleach the hell out of the fabric. So it goes.