A few facts you may not know about traditional hand painted cel Animation.
-The invention of the technique is generally attributed to Earl Hurd, who patented the process in 1914. The outline of the images are drawn on the front of the cel while colors are painted on the back to eliminate brushstrokes.
-Many studios including Disney simply wiped cels clean and reused them to save the cost of new sheets. Therefor examples from early animated movies and cartoons are hard to find.
-"The Band Concert" released by Disney in 1935, was the first color Mickey Mouse cartoon. An original cel from the cartoon was sold in a private transaction in 1999 for a reported $420,000 USD.
-Many cartoons and animated movies are still drawn by hand, but on a digital tablet instead of a traditional animation cel. The last cartoon to utilize hand-drawn animation cels was "Ed, Edd, n Eddy" for the Cartoon Network.
-Disney via their Disney Stores sold production cels from The Little Mermaid (their last film to use cels) at prices from $2,500 to $3,500.
-Although it didn't use hand painted animation cels "The Princess and the Frog" is the first Disney movie since 2004 that is completely hand drawn and not computer animated. John Lasseter has stated that he is committed to producing at least one hand drawn feature every two years.