Kallitype

From Wikipedia, the free encyclopedia

1 Summary
2 Chemistry
3 Coating
4 Exposing
5 Processing
6 Sources

[edit] Summary

Patented in 1889 by W. W. J. Nicol, the Kallitype print is an iron-silver process. A chemical process similar to the Van dyke brown based on the use of a combination of ferric and silver salts. Many developing solutions can be used to give a different image color (brown, sepia, blue, maroon and black). Kallitype images generally have a richer tonal range than the cyanotype. These prints were popular in the 19th century, and then their popularity faded away. Sometimes known as "the poor man's platinum print", when the image is toned in platinum or palladium the result is nearly chemically identical to a true Platinotype. It is believed that many Kallitypes were passed off as true Platinotypes and remain in collections as so. Kallitypes have had a reputation over the years as having poor archival qualities and often fading. When properly cleared, Kallitypes are completely archival and will not fade. Toning with a metal such as gold, platinum, or palladium will give extra image permanence. Ferrous ions embedded in the paper as a result of poor clearing is the cause of the lack of belief in image permanence. This can be easily identified by a yellow stain in the highlights.

A Kallitype test print toned in platinum by Zev Schmitz

[edit] Chemistry

While there are many possibly solutions for each step of this process, these are the most commonly used solutions. Each of these has been tested and works well. The sensitizer solutions should not be changed much, but there are many choices in developer as well as clearing solutions.

Sensitizer:

(A) Ferric Oxalate (20% solution - 40g / 200ml H20)

(B) Silver Nitrate (20% solution - 40g / 200ml H20)

Developers: Listed by tone

1. Warm Black tones - Ammonium Citrate (15% solution - 150g / 1000ml H20)

2. Black tones - Sodium Acetate (10% solution - 100g / 1000ml H20)

3. Sepia tones - Rochelle salt (5% solution - 50g / 1000ml H20)

4. Blue-black tones - Rochelle salt (9% solution - 90g / 1000ml H20) + 24g Borax

5. Ultra-black tones - Sodium Acetate (40% solution - 400g / 1000ml H20)

Clearing Baths: Listed by strength

1. Citric Acid (50g) - 1000ml H20

2. Sodium Sulfite (50g) - 1000ml H20

3. EDTA (30g) - 1000ml H20

4. Heico Perma Wash (4oz) + EDTA (30g) - 1000ml H20

5. EDTA (70g) + Sodium Sulfate (70g) - 1000ml H20

6. Potassium Metabisulfate (50g) + Sodium Sulfate (50g) - 1000ml H20

7. Hydrochloric Acid (5% Solution) Extreme care must be taken when using Hydrochloric Acid

Fixer:

Sodium Thiosulfate - 100g Sodium Carbonate - 20g Sodium Sulfate - 4g Water - 2000ml

Toners

Platinum/Palladium Toner - Platinum or Palladium (5ml) + Citric Acid (5g) - 1000ml H20

Gold Toner - Gold Chloride 5% Solution (5ml) + Citric Acid (5g) - 1000ml H20

Hypo Clear

Sodium Sulfite (1% solution - 10g / 1000ml H20)

[edit] Coating

A high quality 100% cotton rag paper is recommended for this process, papers that work well for Platinotype generally work well for this process. All coating must be done under safelight conditions. Gloves are recommended as both sensitizing solutions are quite toxic.

1. Mix equal parts A&B in a shot glass or small graduate. This solution does not keep well and should be used immediately. 3ml will coat a 5x7 image.

2. Use a hake brush or glass coating rod (often referred to as a Puddle Pusher) to apply the emulsion, double coating (letting the first coat dry first) is recommended for a greater dmax. If using a brush the strokes must alternate direct in order to prevent streaking.

3. Let fully dry before exposing, being careful that nothing touches the emulsion while drying.

[edit] Exposing

This is a contact printing process and therefor one must have a negative of equal size to print from. A negative of a density range around 1.8 is optimal. This negative can either be made from a large format camera, ortho litho enlargement, or digital negative.

1. The negative is put over the coated and dried paper, then sandwiched between a board and glass to ensure a good contact. Alternatively a contact print frame may be used for ease of this.

2. The image is exposed to UV light in the sun or under a UV box. On a bright sunny day the image may only need to be exposed for a few minutes. Under a UV box the exposures often range from 5 to 25 minutes.

3. A test strip is advised to figure out the final exposure time with ease.

4. When the shadows of the image are clearly visible and the mid tones look washed out, the exposure should be done. This is called the latent image.

[edit] Processing

There are two methods to processing Kallitypes, the multi-tray and single-tray. When using multi-tray, each part of processing chemistry is layed out in a line in different trays. With single-tray, one tray is used and the chemistry is poured over the image and then back into the bottle. If this method is used, it is best to have a distilled water rinse between baths.

1. Developer - Any of the developers listed above will work, it comes down to preference. Developer #1 is the most commonly used. The developer must cover the entire image as quickly as possible. If any part of the image is not covered it will have a permanent mark. It is best to take a dry tray, place the latent image in it, then pour the developer over it. Agitate continuously for a minimum of three minutes, and no longer than eight minutes. A longer development helps removal of the ferrous ions that make the image unstable. Longer development risks staining. A large amount of silver will quickly build up in the developer and it is best to decant your developer every 5-10 prints, depending on the quantity of developer and size of prints. The dark sludge that builds up in the developer will stain your prints.

2. Clearing Bath - The clearing bath must be used until all yellowness has been removed from the print. Generally this will happen in 2-4 minutes. Starting at the lowest strength clearing bath listed, if the stain will not go away, the next strongest clearing bath should be used. When a clearing bath becomes foggy, it is time to replace it.

3. Toning (optional) - Toning alters the image color and increases permanence dramatically. Toners are often very expensive and as little as possible should be used per print. For the solutions given above, this chart will tell you how much to use:

15ml per 4x5
20ml per 5x7
45ml per 8x10
85ml per 11x14
175ml per 16x20

The toner should be poured over the print evenly in a flat bottom tray and agitated heavily until you are content with the image color, then discarded.

4. Fixer - Fix for 3-4 minutes.

5. Hypo - This bath must be made fresh every time you print, agitate continuously, 1 minute.

6. Final water wash. Wash continuously for 20-30 minutes

==Examples==

Pompey Bread ovens and grain mills Gold Toned Kallitype.

Marseilles Alley Kallitype Rochell salt developer.

Parque Guell Barcelona Sodium Acetate developer.

Kallitype, June Lake Loop Owns Valley California,