QTR-Quadtone RIP

Paul, thank you very much.I am sure that once I have done one it will all become clear !
Chris.

--- In QuadtoneRIP@yahoogroups.com, "pr_roark" <roark.paul@...> wrote:
>
> "bobtail75" <cperfect594@> wrote:
> >
> > In the b&w group Paul Roark said-
> 
> > > I have not tried the Epson Hot Press with the 1800 3MK setup...
> > > There are instructions for making profiles in the notes of
> > > the QTR 3MK "Start" and "Dmax" profiles. If you have a 
> > > flatbed scanner, you'd be able to do this.
> 
> > I have the 2.7.0 QTR but when I go to the 'start' or 'Dmax' 
> > settings as he suggests, the 'notes' page is blank. ...
> 
> I've posted the Notes tab at 
> http://www.paulroark.com/BW-Info/3MK_Profiling_Notes.pdf
> 
> The text is as follows:
> 
> Notes tab of 3MK-Dmax-test & 3MK-Start curves:
> 
> To determine and set the dmax for a new paper and the R800/1800 3MK inkset:
> 
> 1.  Print a 21-step test file with this profile, which is simply 3 straight line curves to 33.3.  See 
> http://www.PaulRoark.com/BW-Info/21-Step.jpg to obtain a copy of the test file.
> 
> 2.  After thoroughly drying the test strip, read the patches.  A spectro is best, but a flatbed scanner will work.  The darkest one is the dmax.  Mark it.  Let's assume it occurred at 65% for this example.
> 
> 3.  Divide 65 by 3: 65/3 = 21.7 (rounded).  This is the ink load that each channel needs to carry at the 100% maximum black point.
> 
> 4.  Open the Curve Creator (Tools>Curve Creation) and open a typical profile, like the one named 3MK-Start.  (On a PC, the relevant profiles are in Program files/QuadToneRip/Profiles/1800-Eboni).  
> (Note that the linearization tab has no numbers in it.)  These instructions are repeated in the Notes 
> tab of the 3MK-Start profile.
> 
> 5.  Rename the 3MK-Start profile with the new paper name, and save it.
> 
> 6.  On the first tab of the Curve Creator, push the "Curve" button for each of the 3 active ink channels.  (Do one at a time, repeating the next instructions 3 times.)  For each of the 3 ink channels you should see the Point List tab's Curve Points, which are the coordinates of the curve used for that ink position.  The paper white is the first point on the left (0, 0), and the last point, for the 100% black, is (100, x), where x, the amount of ink needed to get the best black, is what we are trying to determine here.
> 
> 7.  Set the end point for each of the 3 curves such that each ink carries its (in this example)  21.7 
> load.  Since the ink limit for each channel is 70 (70%), the number that is shown in the curve Point 
> List will be multiplied by 0.7 when QTR reads the profile.  To offset this reduction, we want to raise 
> the number entered in the Point List so that the final ink load is as needed: 21.7 in this example. So, take 21.7 and divide it by 0.7:  21.7/0.7 = 31.  Enter 31 in the last Point List box used: (100, 
> 31).
> 
> 8.  If the change in the end point is large, the curve point coming before it on the curve may need to be changed to keep the curve smooth and with an increasing slope.   This would involve just 
> changing the second number for the coordinate pair just before the end -- 95 for 2 curves, 98 for the third.  Try changing that point's second number by about 1/2 the amount the last box (the 100 point) 
> height was changed.  
> 
> 9. Push the "Preview Curve" button and check that the slope of the line has an increasing slope as it approaches the right (100% black) end of the graph.  That is, the curve should become steeper as it 
> approaches the right side of the graph.
> 
> 10.  Push "OK" and then push the "Create Curve" button on the main Curve Creator interface. It will ask you if you want to save the profile - yes.
> 
> You now have a curve that has the dmax set and is ready to be linearized for the new paper.  To do this print a 21-step test file with the new curve, read test patches with a spectro, from the left to 
> right (white to black), and enter them into the Linearization tab of the new profile.
> 
> For more informatino on the R800/1800 3MK inkset, see 
> http://www.paulroark.com/BW-Info/R1800.pdf
> 
> Paul
> www.PaulRoark.com
>