pop kallitype?

[Colin Graham]

I was printing today and the first one up looked like it fully printed out, i.e the developer hardly changed the print density at all... Anyone ever experience this? The iron and silver getting contaminated with some citric acid is my best wild guess; the effect got successively weaker with later prints, which were in the same order as coated. Odd, but very cool!

 

[Jim Noel]

I would attempt to re-create and note the "error" as this could be very useful.

 

[Colin Graham]

Wish it would have happened to someone more scientific than me... I've got the flu and am running a slight temperature today, so perhaps the entire episode was a fevered dream, lol. But that would be a very interesting process if I can reproduce it.

 

[Loris Medici]

I don't have much experience with Kallitypes (only few test prints) but maybe the paper was very humid during the exposure. High humidity increase the speed and print-out of iron processes considerably. AFAIK, DOP Pt/Pd and Kallitype paper (both use Ferric Oxalate sensitizer) are usually force dried until no humidity is present on paper. Could it be that you left the paper in a very humid environment or forgot to force dry it before exposure?

Regards,
Loris.

 

[Colin Graham]

That would explain a lot Loris. I start exposing very soon after coating and the first sheets were probably still somewhat damp- especially now that the weather has turned cooler. That would also explain the diminishing effect as the printing session went along... So should probably invoke Hakim's razor on this one. Thanks for the insight- not to mention saving me alot of frustration!