PJWphoto

One of the great things about combining traditional photo process work with the information always instantly available on the internet is that I am never short of inspiration for new things to try. Last year one of these things to try came from this post on printing onto fixed silver gelatin paper. The discussion started out looking for a use for unneeded resin coated paper, the most intriguing suggestion came from the ingenious mind of Ron Mowrey (Ex-Kodak emulsion R&D technician who goes by the moniker Photo Engineer). He sugessted using a mix of cyanotype chemistry in gelatin to coat the paper giving a glossy cyanotype image bonded to the coated surface of the paper.

while sorting through my boxes of experiments and test prints, I rediscovered the tests that were sparked by this discussion. As i didn’t have a lot of photo paper that I would consider “spare” I used ilford inkjet paper that stated that it was coated with baryta (the same mineral that is coated onto traditional fiber based black & white photo paper). I found that I had some problems with the emulsion frilling and lifting off the paper, especially at the edges, but I suspect that that may be related to some additional coating that is designed for recieving and drying the inkjet ink.

Additional information, transcribed from my notebook:

• Cyanotype is thickened with gelatin for adhesion and gloss
• Gelatin content should be around 10%
  ie. 50% [sensitiser] / 50% [gelatin 20%]
• Gelatin should be hardened
  10% Glyoxal or Crome alum

  Formailin and Glyoxal will react with ferricyanide over time (heat + time are the enemy)

• Coating of around 10ml per sq foot
• Coating should be hardened for 4 -8 hours

Details of paper coating:

Prepaired in a shot glass @ 40-50 C
• 4ml 20& gelatin
• 2ml Cyanotype sol A
• 2ml Cyanotype sol B
• 1 drop 20% tween20 (non-ionic surfacant)
• 2 drop Formalin (hardener)

  The paper (Ilford FB AL inkjet paper) was coated with the hot gelatin mix using a hake brush, working quickly for an even coat and stopping brushing before the gelatin starts to cool and hold brush strokes.
  the coating was allowed to set for around 30 mins before being hung up on a line to dry.

  while the paper was drying a few dark blue spots appeared which i chalked up to dust or other contaminants in the coating(but there was still enough workable surface for my tests). After 4 hours the surface was smooth, dry and very glossy. however there seemed to be a slight fogging ( probably that reaction with the formalin that Ron warned about) that had turned the sheets a sort of powder blue.

  

  I continued to the exposures without hesitation, using a couple of T-55 negatives that I was familiar with and a couple of recent pinhole shots.
  As you can see in the prints, the fogging remains and there is a slight yellowing that I assume is caused by the gelatin holding onto the unexposed sensitiser. This might have been removed by further washing but as I said earlier I was having problems with the emulsion lifting from the paper and did not want to leave the prints in water longer than necessary. Most of the prints that I found today have wrinkles on the borders as evidence of this.

  I recall that with one print I tried to lift the coating clear of the paper to transfer it to a sheet of water colour paper, ala polaroid emulsion lift. This was sort of successful in that it stayed intact and on the paper until it dried, where it promptly became detached and broke into a million little pieces!