QTR-Quadtone RIP

Thanks Per.
I am familiar with J Keith Schreiber excellent post and I just now read your posts with him. We seem to be on the same path.
The Boutwell DN approach doesn’t work for Silver on the P800 because it requires Magenta as a blocker (print out the inkseperation file to see this).
The DN has Yellow for adjusting which works for UV processes and seems would work well.
Check out www.mprosenberg.com for  good information on Silver Gelatin and his use of a . ACV Curve in the K Ink dropdown choices.
So we have that to tweak plus under the Gray Curve Tab a Tweak plus the Linearization Tab. 
JKS mentions K should only be 15% but I found PK 50-55 on the inkseparation file with MGIV to get White. (Dektol 1:2 etc)

All the Best,
Terry Glass

On Dec 9, 2018, at 8:03 PM, QuadtoneRIP@yahoogroups.com wrote:

QTR-Quadtone RIP Group 
4 Messages Digest #3737 
1a Creating a QTR Profile/Curve by "Terry Glass" firstlight2001 
1b Re: Creating a QTR Profile/Curve by perbjesse 
2a Re: macOS Mojave issues with Print-Tool by peter.ragnarsson 
3 Digital negatives questions by perbjesse 
Messages 
1a Creating a QTR Profile/Curve 
Sat Dec 8, 2018 7:45 pm (PST) . Posted by: "Terry Glass" firstlight2001 
I’m having trouble wrapping my brain around selecting Limits and Densities and other settings to create a Profile for a Digital Negative for Silver Gelatin.
Using a P800 and printing the inkseparation file and the SG readings are:
PK gives white at 55
Magenta gives white at 80
Note Yellow no blocking for tungsten light.
LK Ink almost blocks at 100
Other inks no blocking 
Now what numbers, etc do I put in QTR Curve Creator? I’m on a PC.

Thanks
Terry Glass 
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1b Re: Creating a QTR Profile/Curve 
Sun Dec 9, 2018 3:40 pm (PST) . Posted by: perbjesse 
Hi Terry. I have recently gone through the process to create a silver digital negative profile for a stock p800 from start to end (in fact. my first print using this flow was last night). I would suggest you look at Keith Schreibers page at https://jkschreiber.wordpress.com/platinumpalladium-notes/digital-negatives-with-quadtonerip/ https://jkschreiber.wordpress.com/platinumpalladium-notes/digital-negatives-with-quadtonerip/ and pay attention to the back and forth between me and Keith in the comments. Armed with a densiometer, it was really not too hard to make a workable p800 digital negative profile. Is it the best possible one? I don't know yet. But my first print using this profile looks good on fiber paper. My next step will be to print a high quality inkjet print of the same picture and compare to see if there is a difference in tonal gradation and smoothness between the two versions. The sharpness is defintely good enough. Would piezography be better? Probably. But I am starting where I am at.  

You may also want to know that Walker Blackwell sells a system at bwmastery that aims helps you through the process (https://www.bwmastery.com/quadtoneprofiler-digital-negatives/). I have not tried it, as I wanted to figure things out myself first. It may offer better controls for linearization than just doing a greycurve and then linearizing. If you try it, let me know what you think. 
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2a Re: macOS Mojave issues with Print-Tool 
Sun Dec 9, 2018 1:24 am (PST) . Posted by: peter.ragnarsson 
Hi Roy 

I run QTR with macOS Mojave 10.14.2 
Everything seems to work good. 


But there is a warning sign that say: 
quad to printer app will not work with future upgrades of macOS. 
(when macOS drops 32 bit data i think) 


Thank You for Your work! 
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3 Digital negatives questions 
Sun Dec 9, 2018 4:53 pm (PST) . Posted by: perbjesse 
I am just starting out down the merry slope of digital negatives with QTR, and I had some questions for the experts in the forum: 


1) Is there a way to relinarize a profile after it has been graycurved and linearized? For normal printing, I have used QTR-Linearize-Quad to do this, but I wouldn't know how to communicate to this applet that the densiometer readings I feed it is for a negative flow where the readings have to be interpreted differently. 
My current profile is not bad at all, but it is not quite as nice and regular as my custom inkjet printing profile so I would like to see if I can do even better. 


2) I am printing negatives on 8.5x11 film to contact print on 8x10 paper. My first attempt of this was to generate a 8x10 inverted picture with a black internal border and then increase canvas size to 8.5x11 and print this using QTR. However, QTR insists to shrink the 8.5x11 to 97% (it does not allow printing to full width of the paper) which then make the border to cut along too small. I could just make bigger black border so the picture is too big, and then cut it down to exactly 8x10 but the question is then: What are the best ways to cut down letter size negatives to match the paper perfectly in the contact frame? A rotary cutter? Guilliotine? How does one ensure exact centering of the remaining picture? 


3) Are there any good tricks to register negative and paper so they are perfectly aligned? I have a spring back contact frame, but there is always the possibility of minor slippage, so I was curious if there were any good tricks to know? 


Regards, 
-Per 


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