A collection of experimental photographic prints, originally held by the Swan family, which are presumed to date from Joseph Swan's experiments with carbon tissue printing (1850s-1860s), dry plate development (1860s-1870s) and the invention of bromide photographic printing paper (1870s). We know from Sir Joseph Swan's correspondence that his work was always collaborative and that he did receive photographic prints from other scientists and industrialists to illustrate an issue they had experienced or wanted to discuss. These photographic prints are therefore not necessarily Swan's own, they may have been sent to him by friends and associates.
History of Swan's Development of Carbon Tissue Printing
One of the issues with early photography printing processes was a tendency for the images to fade over time. A carbon-based approach was experimented with by various chemists throughout the early nineteenth century, but they struggled to perfect the technique. Carbon prints were certainly impressively permanent, but suffered from high contrast and short tonal range.
Swan’s breakthrough in 1864 was to develop an improved carbon tissue, together with a process for transferring the tissue to different paper supports during the development process. His breakthrough was very much a modification of various experimental processes which had been worked on by a number of chemists internationally. But his modification was crucial, because he took a difficult and complex process and made it so simple it was suitable for mass production.
Swan began marketing carbon materials in 1866, offering his ready-made tissue in three colours: black, sepia and purple-brown.
History of Swan's Development of Bromide Paper
In 1879 Swan was granted a patent for photographic printing-paper coated with bromide of silver.
Swan’s development of bromide paper was another step which made photography far more accessible to the hobbiest. More sensitive than the higher quality silver chloride papers, it was perfect for rapid printing under artificial light. In his patent application Swan emphasised that the short exposure time necessary would ensure successful results for the amateur. This was a very significant development – it didn’t just mean that photography was cheaper and required less equipment, it also meant better and more reliable results for non-professionals.
See SWAN/03 for the history of Swan's development of dry plate photography.