Working with sustainable communication methods is hard. There is no rule book or standard print size, and most of the time there is no printing at all. While it can be difficult, there is nothing more satisfying than finding an effective and sustainable medium.
My new love is homemade spray chalk. A simple cornstarch and water mix combined with a stencil can do wonders. Through trial and error I have come to three conclusions about spray chalk.
1. Don't save it after you use it. Keeping cornstarch and water in a tight place for more than a few hours makes it smell like sweaty boy feet.
2. Transparencies make for the best stencils. Chalk isn't like spray paint; it gets cardboard wet and soggy. Thin plastic transparencies work best.
3. Spray bottles clog. Spray bottles make for a better look, but will clog after one or two runs with a stencil. Instead use sponges. For the best results, make sure the sponges are almost dry, then lighting dab on top of the stencil.