I got the idea for this activity from the May issue of Family Fun. We put some washable paint into ziploc bags, added a little water (mainly because we were running really low on paint in the requested colors), sealed them, and started to play. Emma practiced writing letters, while Johnny smushed the paint around randomly until he discovered he could use his dinosaurs to make footprints and lines:
We’ve had these out for about a week (it has not yet occurred to my children that they could open the bag and make a mess), and Emma in particular has found lots of ways to experiment with them. She has tried looking at pictures through a thin layer of paint, and stepping on the bag to get an impression of her foot.