[7] This film is shot in black and white, primarily in a sort of burnt-out, high-contrast look, until near the end, when it turns color during the section that takes place in a draper's / fabric shop.
The censors, however, didn't realize the meaning of the name, which Portabella explains as the 29 years of darkness that had transpired under Franco.
Photography (cinematography) was by Luis Cuadrado, Lluís Maria Riera was the art director / responsible for decoration, and Teresa Alcocer did the editing, assisted by Margarita Bernet.
[8][14][2] The music was by experimental composer and musician Josep Maria Mestres Quadreny, with Carles Santos on the piano and soprano / mezzo-soprano Anna Ricci singing.
[15][16] The film was shot entirely in Catalonia, with outdoor shots in Barcelona, Portlligat, Les fonts de Sant Hilari Sacalm water springs, Baix Montseny (subcounty around Sant Celoni, near the Montseny Massif), Collformic mountain pass area (in the municipality of El Brull), Arbúcies, Coll de la Pollosa mountain pass (in Collsuspina) and Moià.