I looked up several recipes from a few different websites for finger paint. I had an idea to send my nephew a card since he's still young and we wanted him to know we were thinking of him. The easiest recipe also got some of the best reviews on this site and so I went ahead with that one.
The recipe called for cornstarch and water, something I always have on hand. Cornstarch naturally thickens food when heated so I thought this would be a great recipe to try first.
You simply mix 1/3 cup cornstarch with 1 cup water and heat to boiling. Add the food coloring after it has cooled a bit.
I actually used a lot of food coloring and it still wasn't as dark of a color I would have liked. The mixture will thicken as it heats, too. The mixture got to this point (above) even before boiling so I'd probably use half as much cornstarch and reduce the heat a little for the next attempt.
I added some red food coloring (Camden's favorite color) and smeared it all over his hands. :) He wasn't freaked out and luckily didn't try to eat it. It was really hard, however, to keep his figers spread out since he wanted to keep his fists closed. We did a test print on the white paper (mostly for us), then tried the card we sent to his cousin Elijah.
The finger paint ended up thickening up way more than was necessary and after about 30 minutes it was totally gelatinous and unusable. I would definitely try another recipe for next time. I'm so hesitant to use kool-aid because it stains your fingers so easily.
He was tired since he had just had a play date and it was bed time so he looks less than enthused. He did really well and didn't resist though. I am thinking once he starts eating food we'll try again since none of the recipes I found used anything toxic.