Digital BW, The Print

Very good description,

In the future I belive we will have software configuartions that could create different 
optical smoothness of the dot patterns with a smaller number of inks, who knows, that 
would require a new head technology and a lot of r&d.  But for now it does appear that the 
more greys the better. Just having that ultra light channel in the Piezzotones or Ultratones 
for instance can work wonders with very delicate tonalities. Now Cone is betting his entire 
reputation and future on the fact that they believe the 7 channels of grey will outperform 
everything out there to the degree that there will be a decent market for it. I belive they 
are right, but certainy not a universtal market with the K3's coming out that will allow the 
fine tuning of print hue as well, something else that was never possible in the g. silver 
days. Cost is certainly going to be a significant factor as well.  People have complained for 
years that black and white inkjet imagery just isn't up to darkroom standards. I belive now 
we are going to surpas silver and platinum printing in many ways, not the least of which is 
the ability to control local tonality with curve layers and selective dodging and burning. I'm 
gonna start shoot black and white again. Too bad there isn't a really good glossy surface 
for carbon output. Now that would be nice.

John




--- In DigitalBlackandWhiteThePrint@yahoogroups.com, hogarth@s... wrote:
> dfaprinting wrote:
> 
> > --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Danny
> > Culbertson" <danculb@b...> wrote:
> > > 12 heads can't be far away...
> >
> > Roland, and maybe a Mimaki or two (older), and I believe there were
> > using the same heads as the Epson 9500 (could be wrong), just had
> > four sets. There was an early Colorspan that used 12 HP/Encad type
> > heads that had hardware configuration for the colors, so you didn't
> > need a horribly expensive RIP to drive it.
> >
> > Now how many shades of black do we really need?
> 
> 
> Well, think about it. For example, think how BO works. For black, you 
> get full coverage (that is, the ink dots overlap) of the substrate. As 
> the image tones get lighter, you get less coverage (the ink dots spread 
> out) so the tone is a mix of the color of the substrate ("paper-white") 
> and the black ink. As the tones continue to lighten, you get more 
> spacing between the ink dots and thus more paper-white and less ink 
> coverage. As some point the spacing between the ink dots becomes visible 
> to the naked eye and the tone becomes "grainy." Finally you get to the 
> point where there is little to no ink (white).
> 
> If you now try two inks, you get something different. The dark ink goes 
> from full coverage to partial coverage, but not to zero coverage. The 
> ink dots are closer together and there is less paper-white showing 
> through. The ink dots are not spaced as far apart as with BO because at 
> some point in the tonality, there is a cross over and the lighter ink 
> takes over. The key here is, at this cross over point, is that for the 
> same tone, the dark ink has less coverage and the lighter ink has more. 
> That is, you see less paper-white showing through, and the average 
> distance between ink dots becomes smaller because you are now using two 
> inks..
> 
> As you go up in the number of inks you use, you successively increase 
> the amount of ink coverage for any given tone, and decrease the amount 
> of paper-white showing through, because you are decreasing the average 
> distance between ink dots.
> 
> Two effects. First, your print becomes smoother due to the decrease in 
> the distance between the ink dots. Second, the overall tone of the print 
> becomes more consistent because there is greater ink coverage and less 
> paper-white showing through.
> 
> So, how many shades of black do we really need? It's really a question 
> of print quality - how smooth do you need your print, and how consistent 
> in color?
> 
> All other things being equal, I suspect you can make an acceptable B&W 
> print from three dilutions of black ink. I think that four inks will 
> show an improvement over three. Many people have experimented with six 
> or seven inks and found an improvement over quadtones. Indeed, Cone is 
> starting to roll out a new heptone inkset. Where is the point of 
> diminishing returns? I have no idea. Maybe someone will take one of 
> these 12 channel Rolands and experiment for a while and find out...
> --
> Bruce Watson