Digital BW, The Print

I've come back to this because I just had a query from a customer of mine about magenta shadows in B&W prints from his R1400. I got him to print a 51-step (QTR) target which I then measured with my i1. It looks reasonably neutral, if anything slightly green, and pretty linear too so the profile is doing a reasonable job. Under my 4700K Solux lamps it looks really nice; however, in normal T-H lighting the whole thing is unacceptably red - much worse than my old Lyson QuadBlack prints.

When I measured the 0,0,0 patch I found an L* of 4,2 but a reflectance rising fairly linearly from 0,0033 at 630nm to 0,317 at 730nm  And yes - he assures me that it is genuine Epson ink.

Am I mis-interpreting something here or does the Epson ink suffer from (severe) metamerism?

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Ernst Dinkla <edinkla@...> wrote:
>
> Op 29-11-2010 14:57, Roger Barrett schreef:
> >
> > I used the Ilford Classic for several years with the Lyson QuadBlack
> > (dye) inks in an Epson 1160 and was very pleased with the results.
> > Prints on my wall still look new after 5+ years. Unfortunately it
> > seems that Ilford have now discontinued these papers except in A4.
> >
> > Although I was very pleased with my dye-based B&W they did suffer
> > from some metamerism. I thought that this was a generic problem for
> > dyes because black dyes begin to transmit in the deep red and become
> > almost transparent in the infrared. This was certainly true of the
> > Lyson inks which had a slight red cast in low-temperature tungsten
> > illumination. Are the dyes being talked about here immune to this
> > problem?
> 
> The Lyson dye inks had that problem. The Small Gamut and Lysonic color
> inks too. It isn't dye related in my opinion, more Lyson related.

> -- 
> Met vriendelijke groeten,   Ernst
> 
> Try: http://tech.groups.yahoo.com/group/Wide_Inkjet_Printers/
> 
> |      Dinkla Grafische Techniek      |
> |         www.pigment-print.com        |
> |                 ( unvollendet )                 |
>