“Érase una vez… is a Spanish animated film directed by Alejandro Cirici-Pellicer. The story is based on Cinderella by Charles Perrault, but the film could not have that title because it was already held by the Disney version.
The film’s realization began on March 1, 1949, with a total of 97 employees. The first script was given to Escobar to undertake the comic portion, having total freedom in writing and omitting existing passages in the work of Perrault. After completing the script, the producers told Escobar to undertake the first sketches of the film based on a story set in the eighteenth century, but did not like the end result. Cirici then proposed setting it in the Renaissance.
Escobar asked not to make the characters of Cinderella and the prince to be similar to reality, so Cirici decided to entrust this task to Juan Ferrandiz which had the approval of Escobar himself. Escobar participated in the realization of the other characters plus some new ones. Federico Sevillano was in charge of animation effects.
The production may have included 380,000 drawings, 80,000 cels, 915 kilos of paint, and 557 animated drawings.”