Digital BW, The Print

On 05/01/2008 Ernst Dinkla wrote:
> Metamerism (as we define it here) is caused by changing
> light spectra in general. UV light and UV light +
> fluorescence is just a part of changed light conditions. It
> can happen between two light sources both without UV light.

Yes, OK. You forced me to go away and read up more on pigment ink 
metamerism. I had not appreciated that the greater metamerism of pigments 
was due to the absence of proper mixing that occurs with dyes and dye-sub.

More annoyingly, that it is a human perceptual issue as well. 
http://www.cs.umb.edu/%7Eram/courses/color/albers.htm is fascinating.

> The Lyson Small Gamut dye ink didn't even while its CMY
> saturation was brought to a minimum.

Certainly was highly metameric in the samples I saw. You had to go a long 
way from any sort of neutral tone to try and hide the effects.

> I have used Generations G4 and am using the Vivera Z3100 inkset.

Lucky man :)

> PMMA doesn't block UV. It actually lets more UV through than
> plain glass. 

Again, you're right. I thought it was all grades of acrylic that filtered 
UV. It turns out to be just some special grades like OP-3, which is 
designed for museum/art use.

-- 
Regards

Tony Sleep
http://tonysleep.co.uk