QTR-Quadtone RIP

Hi -- I'm using QTR to make digital negs for carbon and I'm wondering if anyone can tell me how to flatten the slope of the left side (zero end) of my QTR curve. I'm using three inks and I'd like the first to build up gradually because the dark patches on my print fall off too fast from dmax. Or, even better, is there a way to have a little ink in the mix even at zero on the curve? Everything else is perfect. Thanks in advance! Scott W

What do you mean by flatten the slope? Do you mean that the LLK ramps up too quickly and produces too much tonal separation in the shadows of the print? Creating a correction curve should fix this without too much trouble. Getting ink into the 0 patch isn't possible with the QTR tools. I remember (I think it was Kieth Shreiber) posted about the 0 step being reserved for GO and it will not allow you to ink at that step, even if you define it with a specific ink curve to print something like Curve_LLK="0:5 5:40 10:50 ... 100:0"

 Can you post the ink descriptor file as plain text? That will give some clue about where you are and what you're trying to do. 

Richard Boutwell

Richard, I think it was Walker who posted about using GO in 7 (or more) channel printers with Cone’s new PiezoDN system, that you are thinking of. I am currently beta-testing the system but on a 6 channel 1430, so no GO.

Scott, I can’t try to answer your question either, without more info. First, what printer and what inkset. Second, if you are using a 21-step or other step tablet for calibration, a plot of the results you are getting and referring to in your question would be very helpful. Third, what steps have you taken with the profile so far, i.e. Gray Curve, Linearize, etc. 

Keith

Keith Schreiber
jkschreiber.com

> On May 24, 2016, at 9:21 AM, richard@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> What do you mean by flatten the slope? Do you mean that the LLK ramps up too quickly and produces too much tonal separation in the shadows of the print? Creating a correction curve should fix this without too much trouble. Getting ink into the 0 patch isn't possible with the QTR tools. I remember (I think it was Kieth Shreiber) posted about the 0 step being reserved for GO and it will not allow you to ink at that step, even if you define it with a specific ink curve to print something like Curve_LLK="0:5 5:40 10:50 ... 100:0"
> 
> Can you post the ink descriptor file as plain text? That will give some clue about where you are and what you're trying to do. 
> 
> Richard Boutwell 
> 
>

Thanks for the help, that was really what I was asking (can I put ink in the zero position).  I’m trying to get consistent dot patterns in digital negs to make 4-color carbon prints.  I’m using Piezography Methodology 1 inks on an Epson R3000, but only three of the inks give grain-like dots so I’ve eliminated the others, making digital negs on Pictorico (which I hate BTW!).    It would help if I could increase my exposure times when I print the separations by starting with ink in the zero position and increasing from there, but it looks like that’s a no go.  It’s true, I can make a PS curve to fix this, but I was hoping to keep it in QTR and avoid the step.  Thanks again!  Scott