Yahoo Groups archive

Digital BW, The Print

Index last updated: 2026-04-28 22:56 UTC

Message

QTR Curves

2007-09-11 by alistair_owens

Hi All,

[I posted this on the QTR Group as well but I am not sure how active 
it is so am cross posting it here. I trust that is OK but if not 
please feel free to delete this post Mr/s Moderator]

I am currently attempting for the first time to build some curves in 
QTR for some new papers I am trying. I am using a ColorVision 
measuring device. I am using Epson Ultrachrome inks. I am working 
through Tom Moore's very comprehensive instructions.

I have some questions about the Characterizing the Ink Paper 
Combination process:
1. I assume we are only concerned about the black strip on the 
printout to assess ink limit. Is that correct?

2. My black strip looks very blocked up at the darker end. This is 
confirmed by measurements as follows:
55%	1.87
60%	2.00
65%	2.05
70%	2.07
75%	2.13
80%	2.16
85%	2.20
90%	2.22
95%	2.23
100%	2.23
Based on this data, I am tempted to use a limit of 75%. Is this a 
prudent interpretation or would 85% be better?
 
3. I tried 70% just to experiment and the darkest swatch measures 
2.1 - does mean that if I use a 70% ink limit that my dmax becomes 
2.1 on that particular paper?

4. Assuming the answer to (3) above is yes, is the whole 
characterization process about optimising the compromise between dmax 
and blocked up shadows?

Any and all responses very much appreciated.

Thanks and regards

Alistair Owens
owens@...

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.