QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@...> wrote:

> [...] converting an
> image to the QTR-RGB-LAB space is not enough. You also need to use 
Photoshop
> soft proof, using the profile QTR - RGB LAB space as the Device to 
Simulate,
> selecting Relative Colorimetric, Black Point Compensation and 
Simulate Black
> Ink (using PSCS2 terminology).
> 
> Once you set up and select the soft proof you will see the image 
flatten
> quite a bit - I expect a lot closer to your print, although it 
likely still
> won't be perfect. 

Tom,

I must confess I'm a bit confused. I tried soft-proofing earlier with 
no noticable advantage, so I left it aside. Based on your statements 
I tried it again, but like Frans, I don't see any difference 
whatsoever on my monitor with or without softproofing. I also would 
have difficulty to understand why I would see a difference, since if 
the system is well profiled anything should be linear. The typical 
use of softproofing as I know it, e.g. checking out-of-gamut colours, 
is not applicable in B&W printing. 

> That is because, although you are now using the right
> technique, the profiles you are using are generic. If you have a 
measuring
> device, you can use QTR-Create-ICC to create custom ICC profiles for
> specific ink/paper combinations. These can give very close monitor 
print
> registration, assuming the rest of your system is calibrated.

I CAN understand that this step allows you to softproof the effect of 
paper color and ink tone. But once again, if the monitor is well 
calibrated and if the QTR curves are well linearized, I fail to 
understand how the icc profile qreate by QTR-Create-ICC can be 
anything else then a linear profile. What do I miss??

Joost