Digital BW, The Print

Hi Antonis,

Thank you for a very helpful reply. I just sent a reply to Joe 
Berndt of Bowhaus who had asked me for more information just like 
you did.

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Antonis" 
<antonisphoto@y...> wrote:
> 
> Nick,
> 
> you don't mention the printer or OS you use, so the following may 
> be somewhat generic troubleshooting advice :

It's a 1160 running MIS UT-FS quadtone inkset. The paper I'm testing 
now is Photo Rag. I created this profile from scratch because I 
couldn't find anything close enough to use.

> ...
> Not uncommon is the possibility that there is a difference between 
> the dmax you can achieve with a straight diagonal curve vs the one 
> that really prints when you apply the typical steep curve of the 
> black ink. In that case you have to cheat the limit that was 
> determined by Test Patches (or the diagonal ink "curve"), 
> but only enough to produce a "readable" improvement in density. 
> You go any further and you start loosing density again because you 
> flood the paper.
> 
> Antonis

I think you may have hit the nail right on the head here. I did look 
at some profiles provided by IJC/OPM and notice that the ink limit 
for black tends to be 22 with the black ink curve stop short at 
hitting the max value of 255 according to the coordinate system of 
IJC. This may be the reason. My black ink limit tends to be set at 
24 or 25, but mostly 25 because I thought the more the merrier. But 
this according to your experience maybe the reason for my getting a 
low dmax.

I did try cutting back on the dark grey ink so it won't protrude far 
into the darkest black region, but didn't notice any improvement 
probably because I already had a black ink overload.

I will follow your advice in finding out what my black ink limit 
should be. Other than this dmax issue which I think can be resolved 
using your tip the profile created by IJC is excellent. It took me a 
while to create an initial set of curves to create a target for 
linearization.

In doing this I learned to let IJC create me a nice set of numbers 
by providing it with values for the darkest and lightest patch, then 
using these I place the peaks of each ink at appropriate location on 
the 26 zones, then change the Q or the width of the bell shaped 
curves so I got distinct wedges throughout the test strip.

I got an excellent profile alright, except I was a little naive in 
setting the ink limits. Thanks again for your valuable advice.

--nick