Photographs or still images in paper format, whether in black or white or in color, were and still are one of the main visual information supports of the modern era, and one that has several other formats associated with it, including slides, proof prints, and negatives.

Proof prints are an intermediate stage in the process of development of non-digital photos. The photographic roll, a strip of translucent plastic material, is cut into pieces that contain a standard number of pictures, generally between 4 and 6. These strips are subjected to a chemical process, showing, as a final result, images with inverted colors. From these strips the prints are produced on paper.

However, on many occasions, proofs were generated: impressions of the strips, which made it possible to check the quality of the images on paper and the need to produce final copies.

The audiovisual collection of the CDF Archive contains a limited series of proof prints, some of which do not have their printed, final copies counterpart. These are images from the 80's and 90's of the last century, whose contents revolve around Galapagos nature and the work of CDF scientists.