Tangible Media: Removable Storage of Image, Sound, Motion and Data
Tangible Media: Removable Storage of Image, Sound, Motion and Data
Tangible Media: Removable Storage of Image, Sound, Motion and Data
Channels
Collotype

Title:

Occupation for Women (no. 7092)

Date:

c. 1900

Material:

Collotype on paper, cardboard backing

Dimensions:

3¼ × 7 in. (83 × 178 mm)

The collotype process was invented in 1855. Magnification of a collotype reveals the ink to have an irregular reticulated pattern sometimes described as "worm-like." A glass plate is coated with gelatine containing dichromate. The plate is heated for several hours to form the reticulation. A photographic negative is then placed on top of the plate and exposed to light. The coating on the plate hardens proportionally to the amount of light it receives. When the plate is inked, the harder areas will take more ink and the softer less.

Images swapped for cross-eyed viewing
Close up showing the "worm-like" reticulation
References
⌃  Back to citationHorine, David. 2017. The Permanent Stereoview. Stereo World, May/June 2017, 8–13.
⌃  Back to citationKatzman, Mark. 2025. Identification Guide. The Art of the Photogravure. Accessed Jun 27, 2025.
⌃  Back to citationStulik, Dusan C. and Art Kaplan. 2013. Collotype. In The Atlas of Analytical Signatures of Photographic Processes. The Getty Conservation Institute.