We only meet for 1 1/2 hours so to save a little time I pre-cut out the burlap and stapled them to the paper plates and it worked out really well.
I read a little history about fresco painting from the into to the lesson plan. I also showed them some pictures of ancient frescoes from my art history books you can find some images here. I poured out the plaster and while we waited for it to dry up a bit they worked on their designs. I let them use a mixture of soft and oil pastels. They turned out great and I know they all had fun working on them.
After we finished the other co-leaders and I discussed how this has so many possibilities. They look so cool when finished especially when you antique it by creating cracks.