In 1944 she was hired by Walt Disney Studios as a background artist. Her first credit for Disney was the animated short Donald’s Off Day (1944) and subsequently she worked on over twenty animated shorts featuring beloved Disney characters such as Donald Duck, Pluto, Goofy and Chip ‘n’ Dale before being asked to contribute backgrounds to the feature-length production of Cinderella (1950). Much like Mary Blair, Witmer’s work was often surprisingly bold and modern and these two inventive artists both worked together with the animation team behind Alice in Wonderland (1951) and Peter Pan (1953). -http://moviemorlocks.com/2015/12/17/pioneering-women-disney-artists-mary-blair-thelma-witmer/