Macbook to P600 Mystery (lack of separation in argyrotype highlights)

[MurrayMinchin]

I'm confused.

The images below are a Capture One screen shot of the top portion of a photo and an Argyrotype.

In Capture One, I've brought down the larger sky areas between the trees to about a Zone IX 1/2 print value (RGB 240) and the moss on the larger branches is RGB 181 so should print as a Zone VII+ print value. These RGB to print values have been confirmed by printing step tablets.

For some unknown reason the mossy branches are blown out and the sky is where it should be when the Argyrotype is printed. Weird.

I export the edited B&W files from Capture One as 16 bit TIFF's to a folder on my MacBook, then send them to QTR's Print Tool to be printed as negatives on an Epson P600.

Epson ABW mode is checked.
Black point compensation is checked.
Generic Gray Gamma 2.2
Relative Intent
Print Tool Managed. (This might be where the issue is?)

In Capture One, I used the green & yellow sliders to lighten foliage lower in the photograph...somewhere in the background, are these being added again so that they become textureless and blown out?

 

[MurrayMinchin]

Using perpetual license Capture One 22 and Luma Curve for the Argyrotype adjustment curve.

Colour editing done in RGB 1998.

 

[koraks]

For some unknown reason the mossy branches are blown out and the sky is where it should be when the Argyrotype is printed.

I'm not sure if I see what you mean. What I see in the snippet of the argyrotype included in your post is a severe compression of the highlights and upper midtones and possibly fogging, so it basically all bunches together into unseparated tonality. The background of the branches against the sky shows very distinct separation in your digital version, but on the actual print, it's all very closely spaced tones.

I would expect the main issue is either in the printing process, which may not yield good highlight separation due to fogging (e.g. parts of the sensitizer not washing out well), and/or problems with the adjustment curve (i.e. not linearized well for this paper/process combination).

PS: I've taken the liberty to include something about the lack of separation of highlight tones in the title of your thread.