QTR-Quadtone RIP

I'm a new QTR user, trying to make my first curve (Epson 2200, UCmk, 
VFA paper).  I'm confused about the instructions.  The help file says 
to look at the ink pattern page and determine "where the inks seem to 
max out -- i.e. fill the patch."  The user guide says to "look for a 
patch where it appears all the paper is covered with ink."  It seems to 
me each of these statements could be interpreted two different ways: 
1.  Find the first patch in which no paper white shows through, or 2.  
Find the first patch which is not noticeably lighter than the next 
higher patch.  These two interpretations would give me very different 
results, at least for the page I've printed out.  Even under an 8x 
loupe, most of the ink patches for the different color inks look solid 
(i.e., no white paper showing through) as low as 15-20%. Going by the 
second criterion, though, i would choose around 75-80%.  Also, should 
one give each of the seven inks the same weight in making this 
determination?  For example, there is much more visible separation 
among the LK patches than the Y patches.

Larry

I have no comment on your two interpretations of the user guide and help
file, other than to say that your second interpretation seem closer to what
was intended by both documents. The basic objective is to establish the
point where there is no significant increase in density as more ink is put
on the paper. You can do this with a densitometer (or spectro), a scanner or
by eye. In my experience, the actual value selected is not that important as
long as it's reasonably close.

There has been some discussion of this process on this list and on the
DigitalBlackandWhitethePrint list. Some favour printing the InkSeparation
file several times, establishing a separate max and density for each ink,
others (myself included) print one InkSeparation (twice - unlimited and
limited) for all inks, using the K ink to establish the overall limit.

Tom Moore


> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of larry_chait
> Sent: Monday, October 17, 2005 8:30 PM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Hardware ink limit calibration question
> 
> I'm a new QTR user, trying to make my first curve (Epson 2200, UCmk,
> VFA paper).  I'm confused about the instructions.  The help file says
> to look at the ink pattern page and determine "where the inks seem to
> max out -- i.e. fill the patch."  The user guide says to "look for a
> patch where it appears all the paper is covered with ink."  It seems to
> me each of these statements could be interpreted two different ways:
> 1.  Find the first patch in which no paper white shows through, or 2.
> Find the first patch which is not noticeably lighter than the next
> higher patch.  These two interpretations would give me very different
> results, at least for the page I've printed out.  Even under an 8x
> loupe, most of the ink patches for the different color inks look solid
> (i.e., no white paper showing through) as low as 15-20%. Going by the
> second criterion, though, i would choose around 75-80%.  Also, should
> one give each of the seven inks the same weight in making this
> determination?  For example, there is much more visible separation
> among the LK patches than the Y patches.
> 

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