QTR-Quadtone RIP

Frans

Unless indicated otherwise in the curve name, curves usually are designed
for 1440 dpi. Curves designed for 2880, by convention have the term 2880 in
the curve name.

You can use a 1440 curve at 2880 with reasonable success by reducing the ink
limit by about 35%. You can do the converse by increasing the limit by the
same amount.

With regard to matching image and print many QTR users get quite a close
match, but there are a lot of factors involved, including how good your
monitor profiling is. You state that your prints match quite well with the
Epson driver. I presume that refers to printing color images. It could be
that black and white images might make more visible, differences that are
masked by presence of color.

In any event, assuming your monitor is well profiled, simply converting an
image to the QTR-RGB-LAB space is not enough. You also need to use Photoshop
soft proof, using the profile QTR - RGB LAB space as the Device to Simulate,
selecting Relative Colorimetric, Black Point Compensation and Simulate Black
Ink (using PSCS2 terminology).

Once you set up and select the soft proof you will see the image flatten
quite a bit - I expect a lot closer to your print, although it likely still
won't be perfect. That is because, although you are now using the right
technique, the profiles you are using are generic. If you have a measuring
device, you can use QTR-Create-ICC to create custom ICC profiles for
specific ink/paper combinations. These can give very close monitor print
registration, assuming the rest of your system is calibrated.

Good luck

Tom Moore

> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of fwaterlander
> Sent: Monday, February 26, 2007 6:19 PM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Re: Why are Epson 2200 prints too dark
> 
> Joost,
> 
> Thanks for your reply. I indeed use the Epson OEM ink cartridges and
> Windows XP Home Edition.
> 
> After reading more on this forum I changed my dpi from 2880 to 1440
> and now my prints are much lighter, but they are now way too light
> and seem to lack contrast and my blacks are too light as well.
> The QTRgui Help feature nor the User guide say anything very specific
> about what dpi to use, except that on the one hand I am let to
> believe that it doesn't matter much (it matters a lot in my case!)
> and on the other hand it is suggested to change dpi if results are
> not satisfactory; I can't find any definitive instructions on what
> dpi to use and how it would make a difference.
> 
> On your suggestion I converted my image, previously with the Adobe
> RGB (1998) profile, to QTR - Gray Lab and this doesn't change the
> print one bit.
> 
> So, is this the kind of monitor-to-print mismatch that I should
> expect, which would require me to retweak every image before printing
> using QTR? That's hard to believe given the praises that I read about
> the program.
> 
...