Kool Aid is apparently full of citric acid (no surprise), which is a useful fixing agent. If you're using mere food colouring for dyeing, you need a fixative, but the Kool Aid does it all! Not sticky, unless you are very foolish and add sugar, and apparently it shouldn't run. As home dye processes go, it has to be about the least painful one possible! (I understand it can also be used to colour hair. And people *drink* this stuff?)