Soon after the establishment of the Archives of Audiovisual Records (1955), the microfilming began to secure the most valuable collections of the Polish archives. The Central Microfilm Store of the State Archives was set up and comprises:
- security negative microfilms – first generation silver gelatin microfilms in the form of a monochromatic roll film on which tone brightness is the opposite of the picture being reproduced;
- positive security copies – second generation silver gelatin microfilms in the form of a monochromatic roll film on which tone brightness corresponds to the picture being reproduced;
- collection of positive microfilms from registry records made in the course of cooperation with Mormon Genealogical Association;
- positive copies obtained as part of the project of microfilming Polish materials from foreign archives.
These microfilms are not made available and are used to secure the contents and image of the original materials in case they are destructed or lost.
The total number of microfilms as at 31 December 2019 is:
- security negatives: 79 841 570 frames
- positives from registry records: ca. 15 860 000 frames (528 341 lm)
- positive security copies: ca. 60 635 000 frames (2 021 332 lm)