QTR-Quadtone RIP

Hi Daniel,

100% black should stay 100% black in the output.   The most likely reasons for
this not working correctly is the Rendering Intent and Black Point Compensation.
In Photoshop it definitely has to be Perceptual Intent and BPC=On.  Relative
Colormetric often gives reduced dMax.  On Mac's it's simply on the
Print with Preview
page.  But if you use Convert-to-Profile check there as well.  Default
is often set
at Relative.  If you are on a PC and use other editing programs --
Qimage in particular -
it's important to see how it works.

Ernst just mentioned some issues with Qimage so see that thread as well.

Roy


On 6/18/07, Daniel Jackson <dnj@...> wrote:
> I'm trying to create a simple QTR curve. When I linearize it, I do
> indeed get a much straighter luminance curve, but the dmax at
> 100% drops dramatically: when plotted in Excel, the curve
> noticeably tips upwards between 95 and 100, reducing the
> dmax from 1.62 pre-linearization to 1.53 after.
>
> Why is this happening and how do I fix it?
>
> --Daniel
> PS. Gray overlap is set to zero, so I don't think it's related to the
> second ink curve being changed.
>
>