I found this on Ariella's blog, Childhood Magic, and she in turn had discovered it on someone else's blog. We could have done it on T-shirts, as her kids did, but we didn't want to wait until we could get some white T-shirts and so we used what we had on hand, which was squares of white, cotton sheeting.
I drew a dozen different designs on the cloth with Elmer's Washable School Glue Gel and let it dry well. Then we waited for an opportunity. This was Gemma's nap-time, but in order for Dominic and Adrian to take part, I had to let them stay up from their naps (Adrian is really outgrowing the napping, but Dominic really needs his).
I had these cheap, disposable promotional tablecloths and I taped two of them to the schoolroom floor. Then I filled foam egg cartons with acrylic paint, full strength. Out came the brushes, paper towels and wax paper.
The kids had a great time painting these. It took the older ones some time to realize that this was art, not a coloring book, and that it was okay to paint outside the lines. Dominic got that right away.
I hurried up the drying process with a blow dryer. Once the acrylics were dry, I scrubbed them first by hand in hot water with a little dish soap to remove most of the glue. Then I tossed them in the washing machine with hot water and detergent. And then hung them up to dry.
Aren't they lovely? We will definitely have to do T-shirts...