Mike Finley <mike.finley@...> wrote:
Its not necessarily true that fewer colours in the mix would lead to less long term colour shift. Some time ago there was a suggestion that yellow in the mix reduced long term colour shift (yellow fading offisetting the warming of the black inks), ...
That was some time ago. Current Epson, MIS and other MK and non-neutralized PK inks are 100% carbon or a pigment that appears to be close to it and very strong. From what I've seen they are significantly more stable than the color inks. So, with today's modern pigment (not Claria/Noritsu dye) inks, I believe less color is better in terms of image stability.
I used a yellow ink "counter fade" strategy with an old MIS B&W blend. It worked for a while, but it's history. The black "pigment" inks at that time had dye in them to fortify them. The cool dye faded quickly, causing the carbon warmth to show more. So, I added a yellow dye to the light grays that would fade at the same rate as the black's fortifying dye and offset that dye's coolness.
With modern Epson pigments, the ABW use of more than the minimum color inks needed is probably done mostly for smoothness reasons (and maybe to keep the jets clear, and unlikely/cynically to increase Epson's profits). With respect to the smoothing potential of the color inks, I use Claria colors to significantly smooth the 1400/1430 Black Only dots in my B&W QTR profile for the OEM Claria inkset. It does the job very effectively. (see http://www.paulroark.com/BW-Info/1400-Claria-BW.pdf )
Paul