Digital BW, The Print

I don't have any inside info on IP but I'm pretty sure that QTR and IP work
on exactly the same principle.  The color inks have the most metamerism
so both RIPs use a minimum amount of color ink.  Curves/profiles are primarily
black and light-black.   But the light-black especially is nowhere close to
neutral tone, so a smaller amount of light-cyan and light-magenta are added to
neutralize the color tone.  Since we're neutralizing a warm, yellowish light-black
there is no need for yellow and minimizing color pigments therefore means
yellow is not used at all.  I don't think metamerism is an yes/no issue, its a
matter of degree.  So you don't necessarily eliminate it completely, you just
minimize it by minimizing the color pigments.  This also is true of gray inksets
that have the color pigments pre-mixed in.

Roy


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Shilesh Jani" 
<shilesh.jani@s...> wrote:
> 
> Mitch,
> 
> You raise a very important distinction between the canned QTR set-up 
> and IP.  I believe with QTR on UC inks the preponderence of inks 
> layed down are black, and light black.  Light magenta and light cyan 
> are used only to control warm/cool/selenium (although they provide 
> density too).  Yellow is used only on sepia curves.  No use is made 
> of magenta and cyan inks, specifically to reduce/eliminate 
> metamerism.  The Photoblack ink of UC is supposed to be extremely 
> warm (more so than matte black), and is difficult to neutralize with 
> just the light magenta and light cyan.  IP may work differently, but 
> could introduce the dreaded metamerism, and infact I remember seeing 
> a demo of IP where b/w prints were made with specific viewing 
> conditions in mind.  Not an issue for many people - but I find hue 
> shifts rather annoying.
> 
> Shilesh
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "alland20854" 
> <mitcha@m...> wrote:
> > 
> > > You get get stronger black using the photo lack ink on resin 
> coated 
> > > papers, but that introduces bronzing problems and a very warm 
> tone.
> > 
> > I use ImagePrint on Epson Semi-Matte, and there is no problem of a 
> warm tone (i.e., with 
> > Ulttrachrome inks). In any case, the ImagePrint Tint Picker 
> facility allows "toning" in fairly 
> > wide range, also split-toning (IP6). 
> > 
> > However, there is still a bronzing problem which largely disappears 
> by waxing with 
> > Renaissance Wax -- I suppose that spraying with PrintGuard or 
> similar spays has a similar 
> > effect, but I haven't been able to try this because these products 
> are not available here.
> > 
> > But my current solution to bronzing is to laminate the prints: I 
> have the prints hot 
> > laminated with 2-3 coats (glossy surface), which inceases the Dmax 
> and saturation 
> > substantially -- and no one can tell these are not silver prints. 
> Indeed, the look is that of 
> > face-mounted prints on acrylic (plexiglass). Here in Bangkok it 
> costs me only $10 to have 
> > 24x36 inch print hot laminated (by hand) and mounted on MDF with a 
> one-inch frame 
> > behind it, but in the states and Europe, the cost for similar might 
> be around $200. But you 
> > can cold laminate on a press quite inexpensively, I believe.
> > 
> > --Mitch/Bangkok