Yahoo Groups archive

QTR-Quadtone RIP

Index last updated: 2026-04-28 23:12 UTC

Message

Re: [QuadtoneRIP] Print with QTR with LAB Color Space?

2017-10-19 by forums@walkerblackwell.com

> On Oct 19, 2017, at 4:52 PM, calvin.grier@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> 13 and 97 is (13+97)/2 is 55, not 61.5 as you said.

You are correct. Sorry about that. My calculations were off. Typed in the wrong number. Also, I never assign, always embed . . . when dealing w/ grayscale output.

//
 
And I apologize again, I did not see your use of the “K” value until your most recent reply thinking instead you were using L* values. K values will indeed change. Non-tagged will be something like K of 64% (at the L*50 point) and converted/embedded with GG22 will be K 54% (at the L*50). K value is different than L*value which changes very slightly when converting (less than 1%). K percentage shows the difference in the gammas nicely (as a number) but I’ve never used it as a reference point as I find it doesn’t have any bearing really on a properly linearized environment. I prefer simple L* values . . . . sorry for my quibbling and confusion. I probably should not have been typing today! . . .

All the best,
-Walker

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.