Ozotype
The ozotype is a photographic fine printing process from the early days of photography . Thomas Manly invented this method of pigment printing in 1899 , which was later replaced by the Ozobrom process .
It is a variation of the coal pressure . A chrome gelatine paper that has been made light-sensitive with potassium dichromate and manganese sulfate is exposed to a negative using the contact method. The result is an image consisting of brown chromium oxide and manganese chromate . Then a cloth is pressed on, which is soaked with a mixture of carbon pigment, dilute acetic acid and hydroquinone . Due to the tanning effect of the hydroquinone on the chromium-containing image areas created during exposure, the carbon emulsion in the chromium gelatin layer then hardens proportionally to the exposure. The leaves are separated and the unexposed (unhardened) gelatin layer is washed out in warm water.
literature
- Arthur von Hübl : The Ozotype. A method for the production of pigment copies without transfer (= Encyklopadie der Photographie. Heft 47, ZDB -ID 1006803-x ). W. Knapp, Halle (Saale) 1903.
- Thomas Manly: Ozotype. The new carbon printing process without transfer, actinometer or safe edge. (= Amateur Photographer's Library. No. 20). Hazell, Watson, & Viney, London 1900.
- Mark Osterman: Ozotype. In: Michael R. Peres (Ed.): The Focal Encyclopedia of Photography. Digital Imaging, Theory and Applications, History, and Science. 4th edition. Elsevier, Amsterdam et al. 2007, ISBN 978-0-240-80740-9 .
Individual evidence
- ↑ Ozotype on zeno.org
- ↑ Ozotype ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. on notesonphotographs.org
