Italian Ceramics: Deruta and Montelupo Fiorentino

I love Italian ceramics and hope to do some shopping while I'm in Italy this summer. Can anyone tell me more about Deruta--I understand it's filled with shops & artisans. Has anyone been to Montelupo Fiorentino? It's a lot closer to where we're staying in Tuscany than Deruta, but doesn't seem to be as well-known. Thanks in advance for the help & advice!