I am a huge fan of commercial art from the 40s-60s. It’s incredibly beautiful stuff and I just stumbled across a site that focuses on it. It’s called TODAY’S INSPIRATION. If you like the art of the Mad Men era, this place is heaven and has been running for awhile.
Of special interest to comics fans of the silver age comics is there are a lot of articles on there about the Famous Artists School which used to run ads on the back pages of comic books in the 1960s. They’re still around. But this site runs pages from the 1960s magazines they published. Really wonderful material.