Digital BW, The Print

I received a set of sample prints from Lyson (GB) that were made using  
an Epson 2100 and Lyson's QuadBlack Toneable inkset.  The prints I have  
included several matte papers (smooth and textured fine art in two  
weights) and one high gloss RC paper.  I had requested a print on the  
new Darkroom Gloss, but they said in a note that I received with the  
samples that Darkroom Gloss is not recommended for use with this inkset  
in the 2100/2200 printers "because of media weight".  On the plus side,  
the Quadblack Toneable prints had very high dmax and the glossy print  
had no bronzing.  Additionally, the QuadBlack Toneable prints appear to  
have good "depth" and luminance.  Unfortunately, all of these prints  
exhibited severe metamerism, shifting from strong purple/magenta under  
incandescent lighting to slightly greenish in daylight - much more  
pronounced than the metamerism exhibited by the Epson Ultrachromes.   
The 2100/2200 inkset appears to consist of 3 neutral, 2 warm, and 2  
cool inks.  Toning is controlled in Photoshop via the use of channel  
mixer adjustment layers and a softproof icc profile (see user guide  
pdf).
http://www.lyson.com/Technical%20Support/Quad%20Black%20Toneable/ 
QBT_UserGuide.pdf
Based on earlier comments, I understand that there may be a different  
inkset or better behavior with this one on Darkroom Gloss when used  
with a RIP so I look forward to hearing more about these developments.