QTR-Quadtone RIP

> The rest of your method sounds okay with the possible exception of
the black boost of 100. That will probably be overinking but will be
restricted to the very deepest blacks.
> 
> Howard

Howard,

Thank you for your comment about overinking.  Looking more closely at
QTR distributed profiles for Epson 4000, I see a "rule of thumb" that
WARM profiles have Black Boost +10 above Default Ink limit... and that
COOL profiles boost only +5... presumably because cools mix in some
LC/LM and try to avoid overinking by reducing Black Boost.

Following that rule of thumb, I constructed/measured/printed
additional Crane Museo Silver Rag curves:

Curve BlackBoost LClimit LMlimit dMax
Warm1          0       0       0 2.10
Warm2        100       0       0 2.25
Warm3         60       0       0 2.13
Cool2        100      12      12 2.26
Cool4         55      18      18 2.11

The numbers suggest that Black Boost swamps LC/LM Limit for dMax.  The
21-step plots - IN TERMS OF 95/100 PERCEPTUAL TRANSITION - suggest
that Warm2 and Warm3 are identical... and that Cool2 and Cool4 are
identical.  The circular gradients of Keith Cooper's B&W test image
suggest that  Warm2 beats Warm3... and that Cool2 beats Cool 4 (i.e.,
Black Boost 100 creates a smoother gradient than +10/+5 over Default
Ink Limit).

Are these observations due to aberrant Epson 4000 behavior on glossy
papers?  DO Epson 4000 UC/K2 inks behave quite differently on matte
papers?

As a retired scientist/engineer, I'd really welcome some solid theory
and supporting evidence for what to measure and observe.  Any ideas? 
As always, thanks in advance for your patience and considered opinions.

Michael Miller
MiloGiacomoRambaldi@...
Atlanta, GA