Digital BW, The Print

Carl,

If you print a picture with a deep blue sky using UC inks you'll easily 
see a shift from purplish blue to cyan if you move from fluorescent to 
daylight. This is consistent with the shift you would see with a 
"neutral" print printed with the Epson driver. This could indicate that 
either the cyan or the magenta inks (or both) are the cause of 
metamerism, not yellow.

--
Daniel Staver
http://daniel.staver.no

> I agree that the "yellow ink causes metamerism" hypothesis is 
> unverified and probably false, but it would be difficult to test.  
> Metamerism is most apparent in neutral prints so if one created a 
> series of neutral profiles with increasing amounts of yellow added it 
> would be necessary to also add increasing amounts of cyan and magenta 
> to maintain neutrality.  At some point the neutral grays would become 
> metameric, but does the metamerism occur because of the additional 
> yellow ink or the CM?  I suspect it is the latter but I'm not sure how 
> to set up a test to confirm this.  Sepia prints I've made with profiles 
> that use only K,LK, LM, and Y do not appear to be metameric but they 
> are of course also far from neutral.