The Kallitype is an iron and silver process that has been referred to as an imitation platinum print. They may vary in tonality from a rich sepia to a deep cold tone by changing the proportions of the chemicals in the developer. Contrary to popular beliefs Kallitypes have excellent archival characteristics when properly processed.
Sensitizer
Developer variation #1
| Borax | 50.0g | ||||
| Rochelle salts | 37.5g | ||||
| tartaric acid | 3.0g | ||||
| water 125 f | 1000ml |
Developer variation #2
| Borax | 75.0g | ||||
| Rochelle salts | 12.5g | ||||
| tartaric acid | 3.0g | ||||
| water 125 f | 1000ml | ||||
Fixer
| Sodium Thiosulfate | 50.0g | ||||
| unscented household ammonia | 12ml | ||||
| warm water | 1000ml |
Mix the sensitizer just prior to use. Coat the paper and dry thoroughly, don’t over heat the paper while drying.. This will cause staining.
Exposure
Contact print under a suitable light source, I always prefer sunlight. Expose until the image is faintly visible (about 2-7 min at midday in Spring with average negs)
Development
Place the print face down in the developer. The print must be completely immersed without stopping otherwise a watermark will be visible on the finished print. The print develops instantly but needs ten minutes to achieve its complete tonal range. Discard the developer if it becomes too murky. Rinse the print in warm water for 3-5 minutes before fixing for 7-10 minutes
You can change the tone of the print by varying the proportions of the developer chemicals.Developer #1 is cooler than developer #2 and has much clearer highlights. Keep the total weight of the dry chemicals at 125.0g. Increasing the amount of borax while decreasing the Rochelle salts will give you a warmer print. Decreasing the borax while increasing the Rochelle salts will give you a cooler print.
Contrast Control
You can control the contrast by adding 1.5% Ammonium Dichromate to the developer. To raise the contrast to what I consider normal: add 5ml of Dichromate solution to 400ml developer. For more about contrast control consult Dick Steven's book. His proportions are different from mine but the theory is consistent. For comparison you can say that the above formula is roughly equivalent to Stevens's 1.8ml test (I'm ignoring the 3% solubility differential between Sodium & Ammonium Dichromates which at such high dilltions is not enough to effect the outcome.)
Notes
Rochelle salts are otherwise know as sodium or potassium tartrate
You may want to mix enough sensitizer to coat several prints. In which case just multiply the volume of prints by the quantity of chemical in the formula. Make sure the proportions remain correct.
Links
An Essay by Richard Sullivan about the hazards and handling of Silver Nitrate