The first register of the then-named "Photo-cinematic Archive" dates back to July 1, 1951 and united the Laboratory, the Photographic Archive and the Photo Library. At that time the one register was used to inventory an ever increasing number of photos realized by the Laboratory as well as those acquired through donations. In addition photographic plates produced on-site as well as other material and properties of Photo-cinematic Cabinet joined the collection. This situation remained unchanged until 1957 when a new registry was instituted specifically for incoming and outgoing objects and property. However the status of photographic plates and prints remained ambiguous until the 1960's when the register began to be used exclusively for their inventory. At that time the Photo Library was moved into the Library, becoming an independent body and providing a service for photo documentation in addition to that already extant for scholars. Currently the Photo Library contains about 20.000 photographic prints in black and white, 20.000 slides and 6.000 colour prints.
The prints are divided into seven sections:
- Photos of works which are property of the GNAM (paintings, sculptures, graphics);
- Photos of artists' works acquired through donations and exchanges, currently in the Bio-iconographic Archive;
- The layouts of temporary exhibits and those of the museum's permanent collections;
- Documentation relating to the building's various interventions and restorations;
- Cataloguing campaigns;
- Show inauguration and special events: theater, music, conferences, performances etc.;
- Photography collections obtained through donations and acquisitions.