Digital BW, The Print

Tyler

That was really helpful, thank you.  I've clearly got lots to learn!

David Whistance
  -----Original Message-----
  From: DigitalBlackandWhiteThePrint@yahoogroups.com
[mailto:DigitalBlackandWhiteThePrint@yahoogroups.com]On Behalf Of Tyler
Boley
  Sent: 08 January 2007 21:20
  To: DigitalBlackandWhiteThePrint@yahoogroups.com
  Subject: [Digital BW] Re: Improving Dmax of NK7 inks


  --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "David Whistance"
  <david.whistance@...> wrote:
  >
  > Tyler
  >
  > Many thanks for your advice. It looks as though the solution may be to
  > substitute an Eboni cartridge, however you have me intrigued.

  I was afraid of that <G>.

  > What would
  > you generally use underprinting for if it is not to increase Dmax?

  Reasons differ for color or mono inksets. For straight color using a
  RIP and CMYK profiles the black point is generally a "build" of CMYK,
  and the differences we are seeing here are well worth the efforts over
  the RGB driver.

  For mono inkets it's very different. Obvioulsy one main reason would
  be to investigate a better black dmax as you know. Another may be
  longevity. If the K ink changes more than the others, underprinting it
  or "protecting" it with another stable dark gray changes the
  longevity characterristics of the black point in the prints, since
  it's a build. Another reason may simply be visual, not everything is
  determined by specs and it's possible a tinted ink thrown in with the
  K may simply make a more beautful print.
  Or, none of these things may result, it's a matter of playing around.

  > How
  > would you generally underprint?

  With StudioPrint it's not as flexibale as I would like. In a mono
  environment I simply assign another tank to K along with the actual K
  ink. Porportions are not user selectable, though layered vrs
  distributed dots are.
  I don't use K7s, but a dual quad set, so I often have an unused dark
  gray ink to utilize. If they are both already in use, there are other
  tricks...

  > I am not sure whether this information will
  > be of use for either of the RIP's that I use; QTR and Bowhaus OPM,
  however
  > it might be helpful in future.

  I don't know how it may be done with QTR. In some tests long ago it
  seemed to be done with the overlap control, but I was frustrated by
  the increased dots in other parts of the scale since it's applied
  everywhere, not just K. Clearly that control was designed for other
  purposes.
  With Bowhaus I believe you can literally draw any curve you like with
  any ink. In that case I would probably just leave some of the dark
  gray in at 100% instead of pulling it all out under the K. That's what
  we used to do many years ago making our own partitioning curves and
  printing through PressReady in CMYK with a quad set. Many tests were
  done to find the best dmax trying different percenatages of K and the
  darkest gray. With thse old inks it was usually about 99%K and 75%
  dark gray if I recall. Depends on the paper as well of course.
  Hope that helps.
  Tyler



  


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