input on new site?

I'm working on a brand new Flapper Doodle website, and I need some input on one detail. Should the content background be gray or white? I like how the gray looks on the pages for things like printables and paper goods, where all of my images are exactly the same size. But for my art prints, where some images are horizontal and some are vertical, I don't like how that looks against the gray. (I should add, I don't want to make them into squares, I want people to be able to see what orientation the prints will be.)

Which should I pick? I'm completely torn and feedback would be SOOO appreciated! :)