Before the introduction of computers photoreproduction
was the common means to copy architectural drawings.These copies are found in architectural collections as well
as archives, but also in art collections.
Photoreproductions are contact copies, which are produced
through the effect of light but without photographic
This technique was used to produce equal-sized copies of
technical drawings. They were made by taking a technical
drawing which had been drawn on translucent material
and placing it directly against a photosensitised sheet and
exposing it to light. The light sensitive carrier was most
often paper. The components of the chemical solutions
within the sensitized layers of these photoreproductions
vary depending on the copy process.
The chemical composition of the light sensitive components
of these copies and the resulting sensitivity towards
light and environmental conditions require special attention
and care when considering storage and exhibition.
In the seminar the major photoreproduction processes,
(Cyanotype, Vandyke print, Ferrogallic print, Diazotype,
Silver gelatine contact print, Gel lithography, Negrography),
will be explained historically and technically.
The two days provide an opportunity to look at a great
number and variety of original copies under magnification
and to practise the identification of their techniques.
A separate segment will focus on the conservation (storage,
exhibition and treatment) of these different photoreproductions.