We just had our carnival and used Snazaroo(toxic-free paint) on our kids. It lasts a long time (same stuff from our Spring Carnival). A little tip- We used rubber stamps and a inkpad, then filled it in with the face paint. Everyone is an artist this way!
If you forewarn parents that it may take a tiny
bit of scrubbing, but not enough to take off their child's face, acrylic paints work great. Some people will smooth a drop of face cream on first or a smattering of baby powder, but I paint with these all the time and a good handwashing takes it right off. The WalMart here sells them at 44 cents all the time. It's what we use all the time.
Our Harvest Carnival is just around the corner and I realized that I had not ironed out the details for the face painting booth. Does anyone have any ideas for an economical and safe paint for face painting? I have looked at the face painting kits, and they are too expensive. What have others done?