QTR-Quadtone RIP

The 1400, and presumably the 1430, as well as some other printers, are
subject to microbanding unless both of their paper transport rollers are
engaged.  You can look at the inside of the printer and see that those
rollers are more than 1 inch apart.  So, leaving wide margins top and
bottom (portrait orientation) of the paper is the most certain cure.  I
often print images that are 7x9 on letter size paper.  That amount of
margin seems to eliminate the problem, though less is often enough.

I've found that the more inks that are firing in the profile, the less the
problem.  So, for example, the 3 MK 1800 setup might hide the problem
better.  It's also printing a rougher image, which tends to hide
microbanding.

Often the Epson driver dither pattern seems to hide the paper transport
defects better than that used by QTR.  So, you might consider testing the
Epson driver with an ICC profile.

Also, with QTR you can make profiles that use more inks/overlaps.  For
example, take half of the inks and put them in a "toner" channel (call them
"toner" inks instead of "gray" inks).  Have the "toner" channel start with
the LM and you'll never notice a smoothness difference, though with most
papers the highlights may be a bit warmer.  When you do this you split the
ink limit between the "gray" and "toner" channels/inks.  Re-linearize, of
course.

While I think the 1.5 picoliter printers are more subject to this problem
than then 3.5 pl  models, I've seen this problem on some of the 3.5 models
also.

I assume the paper choice is also a major factor -- thicker probably being
worst.

In spite of the top/bottom microbanding tendency I find I can successfully
print my glossy cards on 7x10 Red River Polar Pearl Metallic paper with 1/4
inch top margins.  Critical viewing with images where the subject matter is
a totally smooth sky might show some evidence of the defects, but it's
minimal where I use the 2K2LK inkset. In this case QTR does a better job
than the Epson driver because it's using the inks more efficiently.  I
assume the thinner (and maybe smoother back) paper is a factor.

With Eb6, I have not done a study of which profiles & paper do the best job
with respect to this microbanding.  I tend to pick my paper based on other
criteria and simply use the margins that are necessary.  Most often I print
with 2" margins for serious prints, so there is never an issue.  The
problem crops up most when trying to squeeze the most image size out of a
letter size piece of paper.

I find the top is less likely to microband than the bottom.  That is, while
ideally I want both rollers engaged, the first/main paper feed roller seems
to be better than the exit rollers.

These machines are not perfect, but when we know the limitations and how to
work around them, they can be amazing.

Paul
www.PaulRoark.com




On Tue, Oct 30, 2012 at 1:42 AM, bakerstrten1 <bakerstrt@...> wrote:

> **
>
>
> Hi
>
> Can anyone diagnose my problem? Printing on my Epson 1430 using QTR with
> MIS EB 6 inks results in lines at either end (landscape) of the print. It
> appears to me as if the printer has missed printing on some of it's passes.
> The problem occurs regardless of whether I use the MIS curve or either of
> the two 'straight' QTR curves which come with the program.
> I printed the same file with my R800 on QTR without this problem. Can
> anyone suggest what is causing the problem?
> Thanks
> Michael
>
>  
>


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