We had a 4-year-old birthday party last week for my daughter and a bunch of her friends. She loves dinosaurs, so we were using that as a theme. I wanted to have some kind of fun craft for the kids to do while they were here and did some searching online. I saw some good ideas about having the kids make their own fossils with plaster of Paris and plastic dinosaurs that they would 'bury' and then uncover later at home.
I went looking for plaster of Paris, but came across air-dry modeling clay instead. A glimmer of an idea took shape. What if the kids could make their own fossils with this? I have some sea shells at home and my daughter has a bunch of plastic dinosaurs of various shapes and sizes and they could use those to make impressions in the clay. It takes 2-3 days to dry, so they could play around with it all they wanted during the party and then take it home. It was easy, not too complicated and would give the kids something fun to do.
So I bought two small tubs of the modeling clay and split it up into small lumps in plastic baggies for easy distribution at party time. I had over 20 bags of clay from both tub. We had about 16 kids at the party ranging in age from 20 months to 6 years and some of the younger kids did not do the craft, so it worked out well in terms of quantity.
I bought some small, plastic plates and each child got a lump of clay and a plate. We put all of the 'fossil' materials in the middle of a blanket on the floor and everyone just sat down and made their own fossils. Dinosaur footprints were pretty popular!
The kids seemed to really enjoy it. When they were done, we wrapped some foil over the plate and put the child's name on it with a marker. They were able to take it home later when the party was over. Aside from a little bit of clay residue on their hands and a few clay bits on the blanket, it was not very messy at all. Perfect!