While there is little dispute that Walt Disney was the crown prince of traditional animation, it has been said that the (Max and Dave) Fleischer Studio offered some serious competition.
Let's take a look at some POPEYE background art.
Here is the original POPEYE main title:
Here, rarely seen, the quite wonderful underlying artwork (as always, click to see the enlarged version)
Here's the "Morning, Noon and Night Club" title card (and close-up):
Here, a few choice samples of digitally re-assembled B/G art from the "nautical nightclub!"
Here's the stage door (note Wimpy's Cafe next door!):
This stage door view is a re-created pan B/G: