QTR-Quadtone RIP

Ferdinand,

Thanks for the information. Dealing with this is maddening.
With my old Mac  and 1280, and a prior version of QTR
My prints were beautiful. With the new computer and upgraded
version of QTR etc. the curves are fine but there is this damned
micro banding and I'm at a loss.

Regards,
Paul
On Jul 30, 2008, at 8:37 AM, ferdinand_paris wrote:

> I have one printer set up with piezography inks that I use for B&W.
> For colour I am using an R2400 with Image Specialists pigment inks.
> For a bit of fun (or so I thought) I would try and create some curves
> for the Ilford Gloss on the R2400.
>
> I followed the instructions as per usual, using the
> UCpk-IlfordSmooth-neut curves as the starting point.  I found that I
> needed to use 2880 to avoid some macro banding.  The first set of
> linearisation parameters that I derived were not always increasing (or
> was that decreasing), and QTR refused to linearise.
>
> I decided that I had set the ink limit too high (60%), and repeated
> the ink separation calculations at 55%.  I honestly thought that this
> gave me the right sort of black without overdoing it, and I even
> measured this with the i1.  However the curve I produced was rather
> lumpy, as per this diagram:
>
> http://www.ferdinand-paris.com/2400_bumpy_curve.gif
>
> I guess I should drop the black limit down to 50%, or are there other
> curve parameters that I should be playing with, like the LK & LLK ink
> limits or the "Grey Curve" / "Toner Curve x" Tabs?
>
> What does this lumpy curve tell me about what I might have done wrong?
>  I've successfully created curves on matte papers before and not had
> this problem.
>
> F_P
>
>
>
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