Galley, Kendrick Idaho, Pigment/ Palladium print
This is a easy process that’s great fun. I’ve used it to combine kallitypes or POP palladium with inkjet.
Prepping the image, I enlarge the canvas (black or white, see note below) to accommodate separation targets (I just use asterisks in the corners with a large font). Any adjustments are made and then saved in the master file, unflattened, for future tweaks. After flattening I size it, convert to CMYK and delete the K channel. This Multichannel file is saved with a _CMY tag without further tweaks or edits (it will look odd without the black layer) or mode conversions. Then I backtrack to un-delete the K channel, delete C,M and Y channels instead, and convert to grayscale. Then I use auto levels or add a levels layer to firm up the histogram correcting the black and white points, otherwise the blacks will be weak and the highlights muddy. From there I flatten the layers, invert the image to create a negative, flip horizontally because contact printing the K layer reverses the image, and then save with a _K tag (as a TIF because I print negatives with QTR).
Master file, K layer and CMY layers
I use an Epson 3800 and the settings that work well are Printer managed colors and relative colorimetric from the photoshop dialog box. In the printer setup for the CMY print, I’ve been using Custom color>Advance>Saturation +25 (increases saturation)/ -20 Yellow and Cyan -25 Magenta (restricts black ink usage to minimize dot gain and keeps colors cleaner). All the checkboxes in this GUI are off except ‘Color Controls’. I’ve been setting the dpi to 2880, but 1440 is probably fine for most folks- I sometimes get head banding with 1440 though on my printer so I leave it cranked up. In the ‘Paper Config’ within this GUI, I use .3mm paper thickness and ‘wide’ gap platten settings for 90lb watercolor paper (Arches, Revere) and .4mm and ‘wider’ settings for heavier 140lb stock like BFK and COT320 to avoid head strikes. I’ve been able to use the Auto top-load for 90lb papers but need the front load for 140lb papers. I haven’t tried heavier stock becuase I don’t use it. For media type Premium Luster paper works well with watercolor papers with the described settings. It’s worth mentioning that the CMY printout will look dingy, dim, flat and much too dark. It’s astounding what the black layer will do to brighten and bring the image back to life. It’s worth going through the steps to print the silver or pt/pd layer even if you think your first CMY attempts are way off target, if only to get a handle on how much impact the K printer has.
The printout from the 3800 dries relatively fast so it can be coated with emulsion and printed over soon. I won’t go into the negative printing steps because everyone does that a little differently.
I use relatively mild clearing agents for palladium (ziatype) printing- separate baths of citric acid and sodium sulfite. It’s a wonderful clean printing-out process that needs no harsh developers. For complex processes like kallitypes though I haven’t seen any degradation of the inkjet layer even through sodium citrate or acetate developers, heavy clearing, fixing, long toning and extended washing steps.
*I used to enlarge the canvas as black border for traditional black, sloppy borders popular with alt printers, like the example in this post. Lately though I print the CMY with a white border (no ink) so that the reversed K negative will have a black masking border that keeps the peripheral brushmarks from getting exposed, and gives clean, crisp margins. I find it a little easier to judge final image contrast and highlight clearing this way. I always trim the margins before mounting and framing anyway, and can be surprising how some prints will deflate without the black border propping it up.