QTR-Quadtone RIP

Hi John,

Your description of your qualifications and experience is similar to mine.

I found the best notes to follow were the help file, User guide by Tom Moore.  Where I ran into probems was my print out of the "Ink Test Separation Page" suggested the limit for the black was around 50%, while the article referring to the same printer suggested it was normally around 80% which I initially used.  I am using the Epson 2100 printer.

I use the Colorvision Printfixpro unit, and found this valuable for checking the maximum value, and now need to redo the calibration with this value.

However, after using the linearization process the test print came out excellently.  

I found it best to set up with the system for just 2 inks initially, then when this was working then experiment adding colours to remove the warm tone.  This enabled me to easily print warm, cool and neutral prints.  

If you have any queries on how I went about it e-mail me off list and I will try to help you.  I found initially I had so many sources of information it was confusing, and coming back to the Tom Moore paper was best.

Good luck

Jim Thyer


  ----- Original Message ----- 
  From: johncjmd 
  To: QuadtoneRIP@yahoogroups.com 
  Sent: Friday, September 21, 2007 8:08 AM
  Subject: [QuadtoneRIP] Re: In Curve Creation: understanding ink limit and ink density settings


  I, too have had considerable problems using QTR. The User guide admits
  it is slightly out of date. This sin't the problem. But I am a user of
  computers with considerable experience and have an advanced science
  degree, and I find the description of the process of making a curve very
  difficult to follow. I am trying to make a curve to use Epson Premium
  glossy Photo paper on an R800. The values I get seem very different
  from those given in the example. And although I own an EyeOne, the
  instructions for using it to get the values needed are sketchy to say
  the least. I followed along with the beginning of the tutorial and made
  a new curve, and then attempted to print the step wedge, but the program
  simply does not print my test.
  Now, I fully expect to be removed from this list after less than 24
  hours of membership and my initial post, since the writer of this
  initial post has been accused of whining about something rather than
  making a sincere attempt to get help with a difficult process.
  Please don't get me wrong about all this. QTR is obviously worth
  considerably more than the $50 shareware request. Commercial RIPS are
  exorbitantly expensive, and don't offer usage on smaller printers like
  the R800. But it is not simple to use. I suggest that a list of
  profiles by successful users of various printers might be a useful start
  for those who wish to customize ther curves. And I respectfully
  suggest that those of us with difficulties are not just complaining, but
  asking for help from the more experienced and more knowledgeable.
  --- In QuadtoneRIP@yahoogroups.com, "dlruckus" <dlruckus@...> wrote:
  >
  > Hello David. I will try to help but if anyone has better words, please
  > chip in.
  > Density, as it relates to QTR, means how dark does the ink look once
  > printed on the paper. It's the nature of the relationships between the
  > inks and papers we use to vary with different printers,inks and papers
  > and, to some extent, even in variations in the surrounding environment
  > (eg: humidity,temperatures etc). It is also true that more ink does
  > not necessarily mean darker. There often comes a point where the
  > application of more ink to the paper actually makes it look lighter
  > rather than darker. The use of the terms density and ink limits in QTR
  > are referring to this effect. We all want the maximum darkness(d'max)
  > as dark as possible so we try to limit the amount of ink used to be
  > only just enough to give us the maximum visual blackness we can get.
  > In practice, generally you stop somewhere just before this at a point
  > where increasing the amount of ink laid down stops giving significant
  > increases in density. You do Not want to go beyond that to where you
  > reverse the ever increasing darkness curve.
  > What I just described is in reference to the K ink but it is equally
  > true of the lighter inks(grays). At some point they also will max out
  > in their density and give no more. So when you make the calibration
  > prints within QTR you are, first, trying to determine what the maximum
  > amount of black ink you can use is(limit) and, second, once this is
  > determined, testing for what the darkness of each of the other
  > inks(grays) is at that same limit and specifically in relation to the
  > black ink. Those figures are then used to derive the initial control
  > points used for bringing the various shades in during the printing
  > process so you get the proper distribution of tones.
  > Linearizing is just a continuation of the above process by adjusting
  > the curves that were derived from them such that they give equal steps
  > across the test step tablet and replicate it properly.
  >
  > All said above is a simplification, though I believe accurate, of what
  > the QTR RIP does and or can do. It has many controls and, beyond a few
  > folks who post here, most of us don't have sufficient experience and
  > knowledge of rips overall to be proclaiming much in the way of wisdom
  > in the matter. That is why it sometimes takes a while to get suitable
  > answers to questions. We don't really relish the possibility of being
  > caught out as a case of the blind leading the blind. Most will wait to
  > see if someone far more knowledgeable will answer first. Those people
  > are usually very busy and have limited time to spend in doing so.
  >
  > In regards to this overall thread (Not your query), some of the
  > responses or complaints are a bit like a 5 year old going into a rage
  > because daddy won't teach him to drive the family sedan. Never mind
  > that he's still too small to reach the pedals and can't yet read the
  > road signs.
  >
  > Regards
  > Duane
  >
  >
  >
  > --- In QuadtoneRIP@yahoogroups.com, "David" dkfreed@ wrote:
  > >
  > > I've posted this question before, but didn't really understand the
  > > answers. So again, can someone help me understand what the ink
  density
  > > and ink limit settings do? How are they different, the same? Can
  > > someone give an example of what changing these settings do?
  > >
  > > I have only a layperson's understanding, so looking for help.
  > >
  > > Best, David.
  > >
  >



   

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