U of S | Mailing List Archive | alt-photo-process-l | Exposure times in tricolor gum

Exposure times in tricolor gum

  • To: alt-photo-process-l@usask.ca
  • Subject: Exposure times in tricolor gum
  • From: Loris Medici <mail@loris.medici.name>
  • Date: Tue, 18 Nov 2008 14:20:45 +0200 (EET)
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This goes mainly to tricolor gum printers printing from digital negatives
separately calibrated for each color layer: do you experience any exposure
time variation? If yes, can you please tell me your exposure times (and
dichromate strenght, only if it isn't kept constant) for each layer? I
just want to see if there's a correlation / connection...

I balanced the pigments according to 2Y + 1M + 1C. In other words, my Y
stock paint:gum solution contains 2x paint compared to both M and C
solutions. Using the same coating solution formulation (which is 1 part
paint:gum solution + 1 part gum solution + 2 parts 10% ammonium dichromate
solution), I find that yellow requires the most exposure whereas C
requires the less (M in between). Is this similar in your case?

Thanks in advance,