I saw it as a kid sometime in the 90s and I can't find it for the life of me. I believe it was done by Warner Brothers but I'm not sure. It was incredibly sad and was about how a tree (or possibly just a leaf?) was turned into paper which was then used by maybe a cartoonist (not sure) and ultimately tossed away. I guess it was a metaphor for the cycle of life.
Anyway, I'd be very grateful if anyone knew what I'm talking about.