Until the introduction of 16mm film in 1923, the most common film width was 35mm. Most major laboratories at that time only had equipment to print and process 35mm film. As 16mm became more popular and demand for feature films in 16mm increased in the 1930s, Etablissements André Debrie in Paris, France devised the 35/32mm printing process which used 35mm film with two rows of 16mm perforations, 32mm apart. A similar process used 32mm-wide film with 16mm perforations. These negatives allowed two prints to be made simultaneously before being slit into individual prints.

Until 1950 there were no recognized standards for 35/32mm or 32/16mm film stock. Debrie realized that the slitting process in laboratories did not have the film manufacturers’ precision; if the film was not slit exactly in half, then one of the 16mm films would be oversize and possibly jam in the projector. Debrie therefore decided to make the 32mm film undersize to 31.8mm. US manufacturers made film to this width but eventually altered it to 31.9mm. The reduction in width ensured that if the slitting wasn’t accurate then one print would not be oversized with the potential to become caught in the projector. This continued until the 1950 SMPTE (Society of Motion Picture and Television Engineers) standards for 32mm negative and positive and 35/32mm stocks were issued. Up to that point there were four or five slightly different styles of perforating in use at various times. The new standard reduced the width of the 32mm film by 0.001" to 31.93mm. (Standards Editorial 1951). There were no new standards issued for 35/32mm stock as the standards committee were concerned that 35mm nitrate with 16mm perforations could be slit to make 16mm nitrate film and used at home with the attendant danger of domestic fires. (The 16mm format was specifically developed to only use “safety” or acetate film).

Technicolor used a related, but different, system for making 16mm prints. The company was only able to process 35mm perforated film using its imbibition process, so it first printed a 16mm image down the center of a 35mm film and then re-perforated the 35mm with 16mm perforations before slitting. This was called “single rank printing”. For a relatively short period of time, from approximately 1963 to 1971, Technicolor also made “double rank” 16mm imbibition prints on 35mm stock, similar to conventional 35/32mm printing. 

In the mid-1970s, Technicolor phased out its imbibition printing and switched to standard Eastmancolor negative and print stocks to mass produce 16mm and 8mm prints of feature films. Technicolor’s optical printer reduced 35mm interpositives to either 16mm or 8mm 35/32mm printing negatives while simultaneously performing pan-and-scan cropping on widescreen films. For 8mm reductions (either Standard 8mm or Super 8), four rows of images were printed on 35mm film. After prints were slit to 16mm or 8mm, 3mm of waste film was discarded.

Many commercial laboratories offered this service well into the 1990s or later. Although these methods appear to be no longer in use, Eastman Kodak continues to offer 35mm film with multiple rows of 16mm and 8mm perforations in its current sales catalogues.