The Material History of a Nitrate Film, Part 2: Preservation - Text 3
In a broad sense, the laboratory process follows the same path adopted in the silent era: a duplicate negative (known also as a “preservation negative”) is struck from the master positive. The first copy derived from this negative is called an ‘answer print’, as it will reveal whether or not the preservation negative has reproduced the images of the matrix with a sufficient degree of accuracy.
When all the necessary corrections have been made to ensure a correct exposure for each portion of the film (the so-called “timing” or “grading”), the preservation negative is used to make one or more positive copies. Their technical names are dependent upon the context in which the prints are created: “show print” or “release print” in the laboratory; “viewing print”, “reference copy”, “projection print”, or “access copy” in the museum or archive. Their common denominator is that the prints they refer to are not subject to the same restrictions imposed upon access to the master elements – in this imaginary case study, print 36 – because accidental damage or gradual wear and tear on the exhibition copy will not compromise the survival of the film.
The preservation negative can be used for further copying as required, but not carelessly: if the negative is damaged or destroyed, it may not be possible to produce another one because its matrix has further decomposed in the meanwhile, or no longer exists. Making at least two projection prints – one for screenings in the museum, the other one for loan – helps to delay repeated use of the negative; best practice recommends taking the extra step of duplicating the negative onto a low-contrast positive, whose emulsion is different from those of the projection prints – it is called a “fine grain master” or “intermediate positive” (element 70) –, to be used as an emergency backup, and ideally a “duplicate negative” or “intermediate negative” (element H) from the fine grain master.
The great advantage of this redundancy method is that the preservation negative is never touched, as all projection prints are made from the duplicate negative; the obvious drawbacks are a slight loss of visual information in the second-generation print for projection, and the extra costs involved. Unless a given title is in great demand, archives and museums rarely go beyond the making of a fine grain master. Most of them cannot afford even that: their project comes to completion when a new projection print has been created, in the hope that nothing will happen to the newly created negative. This is the average basic scenario of a film preservation project.
The vast majority of extant silent films were found as projection prints. In the infrequent event that the surviving element is a negative (such as item E in our fictional case study), the preservation workflow is slightly different.
