For my Tiny Experiment this morning I tried paint washes with rubbing alcohol. I tried this two ways. I watched a demo that used watered down acrylic paint but it did not seem to work very well. I switched to water color and got better results. How this technique atcually works is you paint a wash of color onto the paper then drip alcohol over it while the paint is still wet. The alcohol reacts with the paint and creates a spot where the paint does not stick. The best effect is achieved if you do multiple this multiple times allowing the washes to dry in between. This is a very picky technique. If you add too much or too little water it does not work. It also does not work if you no not allow the washes to dry completely between colors. I also noticed that it woks better if each wash is a very different color from the prvious one.