It also turned out that even a good spring-back printing frame was not giving adequate contact. So first thing this morning I re-established the vacuum frame setup.
The OHP negative and oversize sheet of 1 mil mylar are held in perfect contact by the vac frame.
The exposed sheet shows quite a bit of print-out image in the fully exposed border area around the picture and in the shadow areas of the image itself. Just as it should.
The vac frame glass is thick and heavy, and the unit sits farther from the tubes of the light source than a spring frame with the box in "pizza oven" configuration, so as expected about 50% longer exposure was needed than tests with the other setup. A print from the first negative looked right in the developer, as near as you can tell from a print sitting in brown liquid.
After two minutes development the first clearing step is multiple changes of warm water for five minutes.
Second test negative coming along nicely. All four printed well, and all the resolution brought back by the vac frame was clearly visible.
This is a first. Last Wednesday, early in the morning with a slowly clearing sky after a night of rain, I was fascinated by the patterns made by the incoming tide at Newcomb Hollow Beach. For the first time ever, I decided to make a digital capture intended from the outset to be converted to monochrome and printed in palladium. Last night after finishing in the wet darkroom, I selected a capture, worked it up in ACR, then ran it through my batch action to create a digital negative file to output from the 3880. This is the first print from it.
I won't know for certain until the prints are totally dry, but I think I've got everything where I want it. The negative/mylar packages with acid-free interleaf paper are filed away.
Prints look their worst when they are on the drying racks, half dry, but even so these look promising. If the black holds up after drying, it will be the strongest I've ever seen from a straight palladium print. Magnani was a pain to figure out, especially at the same time as establishing the digital negative workflow, but it looks as though it's worth the effort.