Quote Originally Posted by RealGenius View Post
Get a big bottle of isopropyl alcohol from the grocery store. Should be about $2. I run that with some water between colors. If my colors are close enough (say red->orange) and I'm doing a big batch, I'll just use some of the new color to clear out the old.
If you run alcohol between your paint changes make sure you run water through it before adding the next paint. In other words rinse the alcohol out before proceeding. The alcohol does not play nice with the binders in the acrylic.