When we went, it was a rainy day, and we had the place to ourselves. The boys used diecuts, stamps, popsicle sticks, ribbons, paints, markers, glitter, and stickers to make their own creations or copy some great ideas they saw on the wall. They were completely engrossed the entire time, and midway through my youngest son said, "I wish this was my house!". They loved the freedom to make whatever they wanted, using recyclables and art supplies in equal measure. I loved not having to worry about paint on the table!
The owner is a former art teacher; she is personable and warm. The supplies are definitely used, but there is plenty of everything, and if you don't see it, just ask. Whether your kids are artistic or not, I highly recommend open studio at the Purple Hippo!
Good to know: There is a great New York-style deli just around the corner on Chamblee-Dunwoody. It's called Goldberg's Deli and Bagels.