Quote Originally Posted by David Lyga View Post
simply does not get put onto the paper because the white part does not get compromised by any chemical process: it STAYS pure white. THAT is where digital, at least theoretically, provides potentially purer colors.
Yes, but color pureness if a completely different matter than Dmin.

Our eyes have an automatic exposure control, thus any constant amount of density is automatically corrected for IF there is no comparison point in the view at the same time. This trick is constantly used by varying the background color where the prints are mounted; the same prints look totally different when mounted on black instead of white. Mounting a print with limited Dmin on a very slightly gray background makes the print look same than mounting a print with a better Dmin to a white background.

Of course, there is a limit. If the Dmin is really bad, you will need special lighting and mounting place for the print which is not practical anymore. But as the Dmin in RA-4 process as well as Ilfochrome process (which "suffers" from exactly the same "problem") is quite near, or "near enough", to good white, the problem is obvious only when specially seeking for it by comparing to, for example, a copy paper filled with optical brighteners. Cutting the white borders "hides" the problem and so it becomes purely psychological, mattering only those who know it.

But in the end, as the photographs are a medium of visual art, the end result should be what matters. On the other hand, any technology has bunch of invisible problems you just don't know about.

Color pureness you are talking about, on the other hand, or how vivid and rich colors can be reproduced, is more dependent on the dye reflectance spectra.