As a child, she experimented in her grandfather's laboratory; as a chemist, Edith Weyde made a career at the Actien-Gesellschaft für Anilin-Fabrication, or Agfa for short. She developed stabilisers for photographic paper and invented the first photocopying technology.

Edith Weyde was born in Prague on 17 September 1901 and grew up in Aussig on the Elbe in northern Bohemia. Her father came from Austria and was a grammar school teacher. Her grandfather, who had studied botany, zoology and chemistry, owned a laboratory that sparked his granddaughter's interest in scientific experimentation at an early age.

Weyde graduated from high school in 1919 with a general university entrance qualification, but - probably for financial reasons - she did not start studying chemistry straight away, but initially worked for four years as a laboratory assistant at the Austrian Association for Chemical and Metallurgical Production, an industrial company in Aussig.

It was not until 1923 that Weyde began studying chemistry at the Technical University of Dresden. After just four years, she completed her dissertation on "New materials for X-ray screens" and was awarded a doctorate in engineering. Her doctoral supervisor was the chemist Robert Luther (1867-1945), founder and director of the Photographic Institute at TU Dresden and professor of physical chemistry there. Before Luther was appointed to the chair in Dresden, he had worked for a long time as an assistant to Nobel Prize winner in chemistry Wilhelm Ostwald (1853-1932) in Leipzig.

On the recommendation of her doctoral supervisor, Weyde took up a position in the photographic-photochemical laboratory of IG Farben in Oppau near Ludwigshafen in 1928. In 1932, she moved to the Actien-Gesellschaft für Anilin-Fabrication, Agfa for short, in Leverkusen. It was here that her professional and scientific career took off.

Weyde's first tasks at Agfa included optimising photographic paper so that it could be better processed and stored in a warm and humid environment. She developed stabilisers for the photographic layers, thanks to which the papers became tropicalised. Weyde was also involved in the development of the first Agfacolor papers for colour photography. Her responsibilities also included material testing and the assessment of customer complaints. Careful examination of the complaints and intensive research into the causes ultimately led to her most important discovery, the previously unknown diffusion of silver salt in the photographic layers. This undesirable process impaired the quality of the photos and was therefore a reason for numerous customer complaints.

In the classic development process, a negative was first produced, from which the positive, the actual photo, was created in the next step. The photo prints were transferred from the developing bath to the fixing bath in a stack. Weyde realised that unexposed image silver was detached from the developer-damp prints, diffused into the back of the layer above and was fixed there. This resulted in blurred negatives and unsightly stains on the otherwise light-coloured back of the photo.

The discovery of silver salt diffusion gave Weyde the idea of a new technique that developed the negative and positive at the same time, saving an enormous amount of time when making copies. The technique was ideal for the rapid reproduction of important documents, for example in everyday office work, for which the time-consuming photographic process was not suitable. Weyde developed the idea to market maturity.

On 25 January 1942, Agfa received the patent for Weyde's "process for the accelerated production of a photographic positive image from an original". Due to the Second World War, however, the technology known as Copyrapid was not launched on the market until 1949. Immediately after the currency reform in 1948, Agfa invited all well-known German manufacturers of photographic products to design an office photocopier based on Weyde's invention. Walter Eisbein, co-owner of the Stuttgart-based company Trikop, took just eight weeks to do so. His device, called Develop, exceeded all expectations. After the presentation of the new photocopying process, the name "Blitzkopie", used by the manufacturers and inventors, became established.

The Blitzkopie was immediately successful and also conquered other European countries. In the USA, the copying method came onto the market in 1952. As with many innovations, parallel developments took place. At the end of the 1970s, the diffusion copying process was superseded by new technologies such as the Xerox process. Ultimately, however, it is thanks to the chemist Weyde and her inventive spirit that the copying of documents and other papers is so commonplace today.

Edith Weyde died on 10 February 1989 in Kürten, a municipality in North Rhine-Westphalia. Although her brilliant achievements are largely unknown to the general public, Weyde was honoured several times in professional circles. One of the most important honours was the Culture Prize of the German Photographic Society, which she was awarded in 1963.