Our preschool meets in large chunks - a month at a time. There are many pros and cons, but one of the pros is that you can do a full unit without interruption.
One of the units I did was on famous artists. This one I was really excited about - we learned about Degas, Monet, and Van Gough.
We didn't attempt to paint a Degas painting (a little beyond 4 year olds capability), but we DID attempt to learn the techniques of Monet and Van Gough.
I decided to use washable paint (for practicality reasons) but I wished I wouldn't have since the colors would have been better.
But the kids did an AWESOME job.
This is what it was based on:
(when I made the collages picasa moved the names to the middle. very annoying. oh well)
And then Monet's Water Lilies. Definitely a challenge.
They all did such a great job!
Now, when my kindergartner found out I had done this, she was so sad to miss out on the fun. So I had her and her friend (another sister of a boy in my group) do a little class with me too. And we pulled out the real paint this time and I loved what they came up with!!