content: It's easy to mix the plaster, but hard to tell when the right time is to have the child put their hand in. It seemed to set either too slowly or too quickly. It's quite hard getting a 1 or 2 year old to press their hand into the plaster properly, but that's not the product's failure. One thing I must stress is that you make sure to let the plaster dry completely before putting the tin lid on. I put the lid on before it was completely cured and ended up with black mold growing on the underside of the lid.All in all, I find the moldable clay kits much easier to work with, less messy, and they give you more chances for a successful print.