You can see the whole post here of a ton of background art from the critically acclaimed show “Batman the Animated Series”
I was fortunate to work at WB during this time on Animaniacs and had many friends working on BTAS. It was truly a huge amount of incredible talent collected together. One of the coolest concepts they used to give the art that brooding night time feel, was to paint on black poster board instead of white poster board so that everything had this dark feel right from the get go. Truly amazing artwork in this show… hurry and check it out now before someone makes them take it down.