Digital BW, The Print

I am using an Imac G3 and an Epson 7600 with UC Matte black inks on 
Epson Enhanced Matte paper. I have a few questions regarding the 
QuadToneRIP 2.0 beta 8. 

- When I try to print the ink pattern page in calibration mode with a 
resolution of 2880 x 1440 dpi the second half of the page seems to be 
printed over the first half. Is this resolution not supported 
although it appears in the list?

- With a resolution of 1440 x 720 dpi I am able to do all the ink 
limitation and partitioning and the "linearization". But those 
patches of the step wedge where the light black and the black ink 
both contribute to the density have a strange looking dither pattern. 
What is the reason for this ?

- The highlights are very coarse, even when viewed with the naked 
eye. The "dots" are much coarser compared to the output with my 
StudioPrint demo version using the same inks. What could be wrong ?

Many thanks in advance,
Peter

peter baumbach - fine art photography
http://www.pb-photo.com

Hi Peter,

Gimp-print for the 7600/9600 hasn't been tuned for these printers yet.
There are too many 2880dpi options and they are not working correctly.
However with matte paper and matte ink, I don't think the 2880 res should
be used.

I believe that 1440x720 should be the optimal resolution.  Although it
works, you are right that the dots are too big.  I've been working on that
issue and I think I've found the problem.  Once I'm sure all the dots sizes
are being used I can tune the relative sizes.  I don't think this should be
very far away.

I'm not sure what dithering issues you are seeing but it may be because of
the large dots.  Also I've found I like the "ordered" dithering a little better.

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Peter Baumbach" 
<info@p...> wrote:

> I am using an Imac G3 and an Epson 7600 with UC Matte black inks on 
> Epson Enhanced Matte paper. I have a few questions regarding the 
> QuadToneRIP 2.0 beta 8. 
> 
> - When I try to print the ink pattern page in calibration mode with a 
> resolution of 2880 x 1440 dpi the second half of the page seems to be 
> printed over the first half. Is this resolution not supported 
> although it appears in the list?
> 
> - With a resolution of 1440 x 720 dpi I am able to do all the ink 
> limitation and partitioning and the "linearization". But those 
> patches of the step wedge where the light black and the black ink 
> both contribute to the density have a strange looking dither pattern. 
> What is the reason for this ?
> 
> - The highlights are very coarse, even when viewed with the naked 
> eye. The "dots" are much coarser compared to the output with my 
> StudioPrint demo version using the same inks. What could be wrong ?
> 
> Many thanks in advance,
> Peter
> 
> peter baumbach - fine art photography
> http://www.pb-photo.com

Thank  you, Roy.  BTW, the linearization feature works great. I 
measured the step wedge with the Eye One, and everything was done in 
a few minutes.

Peter

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Roy Harrington" 
<roy@h...> wrote:
> 
> Hi Peter,
> 
> Gimp-print for the 7600/9600 hasn't been tuned for these printers 
yet.
> There are too many 2880dpi options and they are not working 
correctly.
> However with matte paper and matte ink, I don't think the 2880 res 
should
> be used.
> 
> I believe that 1440x720 should be the optimal resolution.  Although 
it
> works, you are right that the dots are too big.  I've been working 
on that
> issue and I think I've found the problem.  Once I'm sure all the 
dots sizes
> are being used I can tune the relative sizes.  I don't think this 
should be
> very far away.
> 
> I'm not sure what dithering issues you are seeing but it may be 
because of
> the large dots.  Also I've found I like the "ordered" dithering a 
little better.
> 
> Roy
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Peter 
Baumbach" 
> <info@p...> wrote:
> > I am using an Imac G3 and an Epson 7600 with UC Matte black inks 
on 
> > Epson Enhanced Matte paper. I have a few questions regarding the 
> > QuadToneRIP 2.0 beta 8. 
> > 
> > - When I try to print the ink pattern page in calibration mode 
with a 
> > resolution of 2880 x 1440 dpi the second half of the page seems 
to be 
> > printed over the first half. Is this resolution not supported 
> > although it appears in the list?
> > 
> > - With a resolution of 1440 x 720 dpi I am able to do all the ink 
> > limitation and partitioning and the "linearization". But those 
> > patches of the step wedge where the light black and the black ink 
> > both contribute to the density have a strange looking dither 
pattern. 
> > What is the reason for this ?
> > 
> > - The highlights are very coarse, even when viewed with the naked 
> > eye. The "dots" are much coarser compared to the output with my 
> > StudioPrint demo version using the same inks. What could be 
wrong ?

> > 
> > Many thanks in advance,
> > Peter
> > 
> > peter baumbach - fine art photography
> > http://www.pb-photo.com

Hi all,
I have been getting QTR to work on the 980 with help from Roy. The dot tuning 
needed to be done for that printer as well. Note that this is actually a gimpprint issue 
rather than one at the QTR level.  Basically, the driver needs to have an accurate value 
for the size of the dots, particularly if there is more than one dot size.  On the 980 
the large dots were correct, but the smaller dots were off. The result was bad 
transitions where the dot size chosen by the driver switched over. This was evident as 
a poor gradient in a density range where only one ink was being printed, and gave the 
impression of poor dithering.  Once we got the value of the smaller dots corrected, it 
made a huge difference. I have a print of a portrait of a child where the dot transitions 
in the face are so smooth it is unbelievable. I have looked at it under 6.5x 
magnification and the face is still smooth.  So in a word, hold on for a while, and the 
results will improve dramatically, I am sure. 

I will try and scan this image for upload.

Costa


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Peter Baumbach" 
<info@p...> wrote:

> Thank  you, Roy.  BTW, the linearization feature works great. I 
> measured the step wedge with the Eye One, and everything was done in 
> a few minutes.
> 
> Peter
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Roy Harrington" 
> <roy@h...> wrote:
> > 
> > Hi Peter,
> > 
> > Gimp-print for the 7600/9600 hasn't been tuned for these printers 
> yet.
> > There are too many 2880dpi options and they are not working 
> correctly.
> > However with matte paper and matte ink, I don't think the 2880 res 
> should
> > be used.
> > 
> > I believe that 1440x720 should be the optimal resolution.  Although 
> it
> > works, you are right that the dots are too big.  I've been working 
> on that
> > issue and I think I've found the problem.  Once I'm sure all the 
> dots sizes
> > are being used I can tune the relative sizes.  I don't think this 
> should be
> > very far away.
> > 
> > I'm not sure what dithering issues you are seeing but it may be 
> because of
> > the large dots.  Also I've found I like the "ordered" dithering a 
> little better.
> > 
> > Roy
> >