Digital BW, The Print

Andrew Sharpe <asharpe@...> wrote:
>
> I've looked for a "List Points" box in QTR and I cannot find it.

First, bring up the Curves Creator (Tools>Curve Creation).

Then under the ink you want to profile -- like Black(K) -- scroll down to "Load Curve."  Push the "Curve" button that will appear just to the right.  When you push that button, a box will appear that has 2 tabs.  One of these is "Point List."  Click on that tab.

You'll then have a series of boxes that are the coordinates for the points.  I use this to write complex curves, but more often what I do here is make a straight line curve for the black ink either to set the ink limit or see the black ink distribution at the ink limit for purposes of setting the relative densities for gray ink partitioning in the Curve Creator.  

If I want to find the K ink limit, the curve I generate is K-0-100.  This just takes two point: (0,0) and (100,100).  Check the curve with the "Preview Curve" button at the bottom right of that box.  Usually I get this limit, however, from the first Calibration Print which is made at 100%.  

Often I use the Point List to make a second 21-step of the black ink at the ink limit.  In fact, I usually put this print on the end of the Calibration curve output.  There's room.  For example, today I was profiling a paper that hit a dmax at 40, but it was very low contrast between 30 and 40.  So, I decided to set the K ink limit at 30, and then use the black boost to go the rest of the way to 40 for that ink.  But for the relative densities, I made a 21-step with a K-0-30 straight line curve and used that output to find the relative densities for the other gray inks to be partitioned.  I kept the ink limits for those midtone grays relatively low to make more efficient use of the inks.  With this approach the pre-linearized QTR output is really quite good already.  That makes it linarize very well.

Hope this helps.

Paul
www.PaulRoark.com