Digital BW, The Print

Mark,

The double hit of black your referring to is accomplished by running 
two printers (ie. ink rollers) both loaded with black ink.  In areas of 
solid black, the additional printer lays down another layer of black 
ink (actually beneath the main ink layer).  This effectively increases 
the DMax by further blocking light to the sheet, and produces better 
depth.  This method also works well when running a duotone with, say, 
black and a PMS gray ink.  As with Piezography, the tonal range is 
divided up between the 2 inks, the gray handles the highs, black the 
lows with some mixing in the midtones.  Again, the gray, which goes 
onto the sheet first, underlays the blacks in the deep shadows, 
allowing better maximum black as in the above scenario.  The ultimate 
print is achieved by adding still more printers with additional grays 
to continue to divide the tonal range, and perhaps a gloss varnish for 
the silver print look.  This is where the idea for quad black printing 
initially came from.

Cheers,
Phil
http://philbard.com


--- In DigitalBlackandWhiteThePrint@y..., "Mark Tucker" <mark@m...> 
wrote:
> --- In DigitalBlackandWhiteThePrint@y..., "Martin Wesley" 
> <mwesley250@e...> wrote:
> > This leads me to wonder what you could do with a duo-ink 
> system. Use 
> > the black and a 50% dilution of the black.
> 
> In commercial offset printing, there is a technique known as 
> "double-dot black" printing. I did a poster in that method years 
> ago. I don't know any of the details about it, but my guess is that 
> it's a "budget" way to pump up the richness of the blacks, while 
> still running one color of black only. (If I'm wrong, someone 
> correct me here). So this would be similar to what you're 
> suggesting.
> 
> I just shot a calendar this week for a liquor company. They're 
> known to print only b/w in their ads, and I mean one hit of black 
> only. The designer is nudging them to try to get them to at least 
> spring for a double-dot black, to add as much depth as possible.
> 
> Also in commercial printing, there is general acceptance that you 
> get more richness if you print at least a duotone, a tritone, or 
> even CMYK-neutral to get the most richness out of a B/W image. 
> It makes sense, since you're stacking up all those layers of ink. 
> But wasn't it pretty stunning to see what just ONE hit of black-only 
> could do with the Epson? I totally agree with you about the look of 
> a "B/W photograph". I wish there was a way to run the Black 
> channel at full strength, but then be able to back down all the 
> other five inks in my 7000 to about quarter-strength, to add some 
> richness, but also to eliminate that pesky color crossover.
> 
> -http://marktucker.com