I would really like to give credit where credit is due, but I can’t find the blog where this idea came from! Overall, the activity (Marble Painting) is a pretty popular one and this fantastic activity can now be done mess free!

Sandwich Bag
Two Colors of Fingerpaint (Washable)
Baby Oil
Packing Tape
Put equal parts of paint and baby oil in the bag and seal it, reinforcing it with packing tape. The frame idea came from the blog (of which I am still drawing a blank)…
UPDATE: This wonderful idea is from Valerie, The Frugal Mom!
Farrah had a lot of fun just moving around the paint and watching it swirl… The feeling of it under her fingers was pretty cool and she mushed the bag and poked at the paint.