Astonishing document being sold at the moment on ebay with the caption:

[In April of 1931, the Walt Disney studio changed its distribution of its cartoons from Columbia pictures to united artists with a better contact which meant not only more money for production, but also more security for its artists and employees. To celebrate the occasion, a special party was held for the employees and offered here is a rare copy of that 1931 invitation. It comes folded and measures 6 1/2"x 8 1/4" and printed on quality stock.]