Wow, Kirk, your review of the prints I made from your files is most flattering. Thank you for your kind words.
I do agree with you that our prints are not interchangeable because of the different choices of paper, inks and degree of warmth. (And they probably should not be exhibited side by side.) The kind of photography I enjoy most is capturing candid moments involving people, i.e., street photography. For that I like strong contrast, sharpness and cool tonality. Very different from the images in this exercise.
Full disclosure: I did actually add sharpening. The technique is a very restrictive edge sharpening process developed by John Brownlow and first appeared in Luminous Landscape back in 2001*. The effect is to enhance the apparent contrast of the entire image without introducing local artifacts. In my opinion, it's much less intrusive than the more commonly used sharpening methods, at least at my skill level.
I also used slight Curves adjustments in each of the images, again because of my bias toward higher contrast - but not at the expense of shadow detail, as you have noted.
I think your observation that the different shades of gray in my prints show slight tinting under mixed lighting is on the mark. The Cone inks in these prints are not pure carbon pigments; I believe Jon Cone adds color pigments to achieve varying degrees of warmth/coolness. Pure carbon is slightly brownish rather than pure black, and the resulting prints would be correspondingly warm. The price of adding color pigments, however, is reduced longevity; one can hope the price is not too high. I have some prints into Aardenburg Imaging for rigorous fade testing.
The lighting in my (dry) basement studio is a mish-mash of 5000K and 6300K overheads, and your comments suggest I should pay more attention to this important detail. Ott lamp on the way.
In an earlier post I said there were 5 files, but, in fact there are 6. After sending the prints to you I decided to print one of the remaining three, HighKey.tif. I applied 3 separate curve adjustments, and I'm still not satisfied. I suspect that if I knew how to use Lightroom (which I have on my machine,) I could get to the print this file deserves. Your print of this image is beautiful. I don't believe either of the other 2 files would present a comparable challenge.
The purpose of this exercise - while it was fun and challenging - was to explore the question, whither piezography for grayscale printing? The observations in your post are incisive. To satisfy a wide range of photo subjects, the best of all worlds would probably be to have two printers, one of which would be dedicated to B&W printing.
HFL
*
http://luminous-landscape.com/tutorials/smart-sharp-shtml