QTR-Quadtone RIP

I am hoping someone in this group might be able to give me a little
advice...
I am attempting to print digital negatives for silver prints. I am
printing on Pictorico White Film on an Epson R1800 using the K7
Piezography inkset and QTR.  The problem I need to solve is I have
banding in the sky in my images. At the point of almost giving up, I
found this article (link below with attached .pdf) 

http://www.digital-negatives.com/index_quadtone.htm

To summarize the article, it is from Ron Reeder, one of the authors on
a great new book "Digital Negatives". He describes that in his High
Key images he also had banding in the sky.  He goes on to say he spoke
with Roy Harrington at QTR who helped him in writing a QTR profile.

I realize Reeder lists the steps to create a QTR profile for OHP film
for a Epson 4000 using Epson inks for Palladium Prints and not exactly
what I need.  But it's close, I think I could solve the banding
problem if I too could adjust one of the K7 QTR curves. So this is
where I thought I would check with this group for any advice because I
realize this is going to be tough.  Any help would be much
appreciated! Thank you so much!! -Victoria

Hi Victoria,

I'm sure there will be members with more expertise around, but some 
comments. I've no expertise with the K7 inks (I'm working with the 
MIS UT3D inks), but from earlier discussions here I learned that it 
is not obvious to create QTR curves for these inks. The K7 curves 
distributed with QTR are not actually created with QTR but with 
special software from Piezography. The reason is that QTR assumes 3 
overlapping gray inks, while the Piezoggraphy curves have up to 5 
overlapping gray inks, each with a different density. I scanned 
quickly the article you're referring to and it seems to assume Epson 
OEM inks, with different colors but overlapping densities. In those 
curves, QTR can use the color inks as "toners" effectively allowing 
more inks in the same density range. There are workarounds discussed 
earlier in this forum, but I'm not too familiar with them.

Also my UT3D inks would allow to fire 5 or 6 inks (different tones, 
comaprable density) simultanuously. Not sure that reduces banding, 
but Roy seemed to have suggested that to you. We have had some 
discussion on QTR-banding issues here recently, but that didn't 
really come to a conclusion.

A standard technique to reduce banding, nothing to do with printing 
curves, is to add just a bit of noise in the critical areas with 
Photshop. Perhaps that is an approach that would work??

Joost

  

--- In QuadtoneRIP@yahoogroups.com, "bjorklundvicky" 
<victoria.bjorklund@...> wrote:
>
> I am hoping someone in this group might be able to give me a little
> advice...
> I am attempting to print digital negatives for silver prints. I am
> printing on Pictorico White Film on an Epson R1800 using the K7
> Piezography inkset and QTR.  The problem I need to solve is I have
> banding in the sky in my images. At the point of almost giving up, I
> found this article (link below with attached .pdf) 
> 
> http://www.digital-negatives.com/index_quadtone.htm
> 
> To summarize the article, it is from Ron Reeder, one of the authors 
on
> a great new book "Digital Negatives". He describes that in his High
> Key images he also had banding in the sky.  He goes on to say he 
spoke
> with Roy Harrington at QTR who helped him in writing a QTR profile.
> 
> I realize Reeder lists the steps to create a QTR profile for OHP 
film
> for a Epson 4000 using Epson inks for Palladium Prints and not 
exactly
> what I need.  But it's close, I think I could solve the banding
> problem if I too could adjust one of the K7 QTR curves. So this is
> where I thought I would check with this group for any advice 
because I

> realize this is going to be tough.  Any help would be much
> appreciated! Thank you so much!! -Victoria
>