Oh, an acquaintance of mine found something like that on pinterest a while back. I bought the strongest big freezer bags and I use acrylic paint because it's cheap from the dollar store and squeeze in 3-4 globs of different colours in the bag and put in a couple tablespoons of vegetable oil and zip it up. You can also add glitter or small round objects that won't puncture the bag. This is great to have in your bag of tricks when they are begging to paint and you don't have time for all that entails. At the end of the day you just throw the bag away, but this keeps my group going for hours sometimes. Oh yes, for the very small babies I use a regular sized ziplock bag on their booster trays.