It is so simple it's ridiculous. Just put a small amount of paint in a gallon-sized ziploc bag. (I used about 1/4 cup of blue finger paint.) Lay it flat and spread out the paint so that a thin layer covers the whole bag, and then zip closed with as little air inside as possible. Done. Let kid play as desired.
One of my favorite things about it was that there was no mess to clean up! This is not usually the case with paint. And it's reusable, which is also not usually the case with paint. Win!
You'll note at the end that he picked it up and looked through it - made me wonder if some kind of stained-glass thingy might be possible with this technique... I don't think Elias is ready for that yet. I'll file that away in my "maybe someday" list.
So if any of my blog readers are Pinterest users (and I know there are some!), then consider doing your own Pinday post and linking up on Angie's blog! The more the merrier! It doesn't have to be something you've actually done from a Pinday inspiration... Even just an idea that you like or want to do someday. Her linky will be open til the end of the week, so blog about something awesome you found on Pinterest. Every Tuesday - be there!