Kallitypie

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The kallitypie (from ancient Greek κάλλος kállos "beauty" and τύπος týpos "image") - also known as brown print , sepia print , Vandyke process , Van Dyke brown or argentotype - is an early photographic technique that was used in the 19th century was very common (English: calitype, caliotype). It is not to be confused with the calotype patented in 1841 by the private scholar William Henry Fox Talbot , but was first made in 1889 by the English chemistry lecturerWWJ Nichol patented. In the period that followed, Nichol applied for patents for other modified fine printing techniques.

The technique is based on the argentotype process known from 1850. In contrast to the silver-free cyanotype , here silver nitrate is converted into metallic silver (using light-sensitive iron salts). The recipe for the kallitypie has been changed several times and every art printer uses its special mixing ratio. One popular method is to work by John Herschel attributable Van Dyke Brown .

Similar results can be achieved with the kallitypie as with the much more expensive platinum-palladium print , which means that many of the prints issued as platinum-palladium prints are actually callitypies.

The similarity of call types with platinum-palladium prints is achieved above all in formulations that use iron (III) oxalate as a light-sensitive substance and are developed after copying out (this process is essentially analogous to platinum-palladium printing) and additionally be toned with platinum or palladium toners. The only difference between the process is the additional intermediate step of silver painting and the significantly reduced use of the expensive precious metals platinum and palladium.

Van Dyke copies which use ammonium iron citrate as a light-sensitive substance are the above. The risk of confusion is significantly less exposed, especially without appropriate toning, i.e. as a pure silver image.

Kallitypie describes a blueprint paper that has been prepared with a mixture of iron (III) oxalate and silver salt . It is similar to the Van Dyke-Braun process . Exposure creates a faint image, which becomes vivid when potassium oxalate , sodium citrate, etc. are poured over it. Kallitypie papers produced matt, neutral black copies that were also toned with gold or platinum salts. Three different chemical solutions are used to create different image colors. Calliotypes usually have a richer tonal range than the cyanotype .

Darkroom technology

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Sensitization solution (light-sensitive substances)

Make up to 300 ml with distilled water.

developer

For sepia tones

Make up to 950 ml with distilled water.

For blue-black tones

  • 24 g borax
  • 90 g of potassium sodium tartrate
  • 1.5 g potassium dichromate

Make up to 950 ml with distilled water.

For neutral black tints

  • 90 g borax
  • 68 g of potassium sodium tartrate
  • 1.2 g potassium dichromate

Make up to 950 ml with distilled water.

Fixer

Dissolve in 750 ml of distilled water and then make up to 1 liter.

Irrigation aid

Dissolve in 1000 ml of distilled water. Prepare freshly before use and use only once.

procedure

  1. Spray the paper with household starch and let it dry. With some papers, this may also be dispensed with.
  2. The sensitization solution is applied to the paper in cross layers. Drying takes place in the dark.
  3. The paper is exposed visually until the tint appears to be correct.
  4. Then it is developed. The correct development time must be observed. Otherwise there is a risk of overdevelopment.
  5. Rinse with clean water for two minutes.
  6. Fixing in the fixer.
  7. Then soak it in water and let it dry flat at room temperature.

Attention! Potassium dichromate is carcinogenic and toxic!

literature

  • Kallitypie preparation. Pp. 65–68, 205–206 in: Photographische Mitteilungen. 47th year, Berlin 1910.
  • Wolfgang Autenrieth: New and old techniques of etching and fine printing. From witch's meal and dragon's blood to the photopolymer layer. Tips, tricks, instructions and recipes from five centuries - An alchemistic workshop book 6th edition, Krauchenwies 2010, ISBN 978-3-00-035619-3 ( table of contents , (→ excerpts online) )

Web links