I previously wrote a whole how to blog on how I do this particular technique over on Modern Rosies, you can find that whole piece here...
Since it is one of the many things I am doing today in building mail art I thought I would reiterate how much I enjoy the effect.
Here is my before shot, a series of cards I hand screen printed on using plastisol ink. Since the plastisol is plastic like and it is already cured the bleach does nothing to it and works rather well as a barrier to help keep the bleach where you want it. Granted I still make mistakes and bleach outside the lines on occasion anyway.
And my after shot
I like this as in ways it is easier for me to bleach the color back out of the paper then to repaint or color it in white. Now to go run off and finish coloring them, adding new backgrounds or whatever I feel like doing with them next.