I have had this problem with my Vandykes using Platine, whereas the Stonehenge paper has always worked well under the same circumstances. I have always thought that it was due to Platine needing more humidity to print. I'm fairly sure that a higher humidity allows the paper to absorb more sensitizer. Using too much sensitizer could also be problematic as the paper isn't able to absorb all the sensitizer in areas, the area which are exposed on the surface end up washing away in the clearing bath. This leaves a low dmax mottled print which could be also said to be grainy. Dan, how much sensitizer are you using and for what size of print? Also, what is the Relative Humidity where you're working? I usually coat in a room of around 60% humidity. This is apparently around optimum level for all iron processes.
cheers david
On 2-Jun-08, at 11:09 AM, dan jones wrote: I have just started working with the process and have had a reasonable amount of success so far. Today my prints started to get a very pronounced grain pattern. the grain appeared with both digital and camera negatives.
Could this be related to humidity/dryness of the coated papers? Or could it be a chemical (ferric oxalate) problem? No change in paper (stonhenge) or developer (sodium citrate). Coated papers are air dried with a fan, no heat applied.
Thanks Dan
david drake photography www.daviddrakephotography.com
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