Instead of the finished work of art, I'm often more interested in the palette the artist created when painting it.
I've always had a thing for artists palettes, including the shape with the little thumb hole in it. On a recent trip to New York, I stopped into Partners & Spade and saw that they had a sweet collection of amazingly glopped-on, paint-spattered antique artist palettes for sale. As with most of the humorous and completely random collections at Partners & Spade, they are one-of-a-kind and prices vary.
The thing I like best about artist palettes is that they're not planned and they aren't even intended to be works of art — but they give a glimpse into the artists process when they painted whatever they painted. And they show that the process can be just as beautiful (if not more) than the end result!
See more at Partners & Spade | Artist Palettes — the palettes I saw in the store were unframed, although it looks like they are selling them framed with custom mattes in antique gold frames.