Kallitype

The Kallitype (also - depending on the recipe - called brown print, sepia print, Vandyke process, Van Dyke Brown, Argentotypie ) is an early photographic technique in the 19th century was very common (English: calitype, caliotype ). It is not to be confused with the 1841 patented by the private scholar William Henry Fox Talbot calotype, but was first patented in 1889 by the English Chemiedozententagung WWJ Nichol. Nichol did apply for a patent in the subsequent period still further modified Darkroom techniques.

The technique is based on the Argentotypieprozess known already from the year 1850. Unlike the silver-free cyanotype here silver nitrate is converted to silver metal (using photosensitive iron salts). The recipe for the Kallitype has been changed several times and every art - Printer uses his special mixing ratio. A popular method is attributable to the work of John Herschel Van Dyke Brown.

With the Kallitype can be similarly good results as with the much more expensive platinum -palladium print, which meant that it is indeed Kallitypien many deductions issued as platinum -palladium printing.

The similarity of Kallitypien with platinum -palladium printing is achieved mainly with recipes that use iron (III ) oxalate as a light-sensitive substance and are fully developed by the Knockout ( this process is essentially analogous to the platinum -palladium printing) and in addition be toned with platinum or palladium toners. Here, the process differs ultimately only by the additional intermediate step of the silver image and the significantly reduced use of expensive noble metals platinum or palladium.

Van Dyke copies which use Ammoniumeisenzitrat as photosensitive substance are the above Confusion significantly less exposed, especially without proper toning, ie as pure silver image.

Kallitype describes a blueprint paper, which was prepared with a mixture of iron (III ) oxalate and silver salt. It is similar to the Van Dyke Brown process. Through exposure produces a faint image that is strong when perfusion with potassium oxalate, sodium citrate, etc.. Kallitypiepapiere were dull, neutral black copies that were toned with gold or platinum salts. There are used three different chemical solutions in order to achieve various image colors. Kalliotypien usually have a richer tonal range than the cyanotype.

Darkroom technique

Sensitizing solution (photosensitive material)

  • 50 g of iron (III ) oxalate
  • 3 g of oxalic acid
  • 25 g of silver nitrate

Add distilled water to 300 ml.

Developer

For Sepia Tones

  • 45 g of potassium sodium tartrate ( KNa ( C4H4O6 ) · 4H2O )
  • 1.5 g of potassium dichromate

Add distilled water to 950 ml.

For blue-black Toning

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

Add distilled water to 950 ml.

For neutral - black tints

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

Add distilled water to 950 ml.

Fixer

  • 50 g of sodium thiosulfate
  • 10 g of sodium carbonate
  • 2 g of sodium sulfite

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

Washing aid

Solved in 1000 ml of distilled water. Prepare fresh before use and use only once.

Expiration

Caution! Potassium dichromate is carcinogenic and toxic!

List of photographic processes Trisodium citrate
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