I've found with my elementary students that it works better if I put a set
amount of paint at their tables in palletes. Only I can refill the palletes.
I don't allow the class to leave unless their table is clean and materials
are put away as directed. I will also assign some helpers each class to help
supervise some aspects of clean up, such as collecting brushes and soaking
them. I usually clean brushes used for acrylics or tempera. Their idea of
clean and my idea of clean are two different things. I also tell them that I
only have so much money to buy supplies and if they abuse the materials,
they'll be stuck using crayons the rest of the year! So far, only a few
problems. Some of my fifth graders try to get away with dropping everything
in the sink.
Try to move around the room frequently. If the kids know you're on top of
what they are doing, you'll have less problems. Janet