I am looking for the same and planned on ordering from Good Time Attractions. Their website is egoodtimeattractions.com. Great question. I never would have thought it would take so much paint. Have a fun event!
I just ordered from rinovelty but am not happy that they only take visa/mc and don't give an exact shipping charge at checkout time. Where else is everyone buying their hair painting colors spray?
I can't give you a number of heads answer but we just did this at our spring carnival. We have roughly 325 students at our school. This booth was popular. We ordered 24 cans from Rhode Island Novelty. (you can find them on the web at I belive rinovelty.com) We ended up having about 7 cans left over. Hope this helps.
I wish I had the answer for you - and no matter what answer you get, it will vary depending on how heavily the person applying it sprays, how much hair is being covered, if it's light or dark hair-which may take more paint.
We did hair painting at our event a few weeks ago. It was wildly popular and parents went to the store TWICE to buy more cans of paint.
I'll see if I can find out any further details, but I think the best bet would be for you to round up some kids as test subjects and see how far one can goes on a variety of heads.