Digital BW, The Print

Hello Wiffle,

>I agree it is some kind of "ink starvation" and that the driver
>needs to be telling the heads to spray more ink on the darkest 
>tones somehow.

It might be a bad cart, try another and see if it goes away (it
happened to me once).  


>This leads me to another question:  what good are paper profiles
>when you are doing Black Only?  

Not much if you're talking about pre-written profiles of some sort.  
Any pre-written profile is created with a particular system and is
good only for that system.


>Has anyone made "Black Only" paper profiles

Yes, sort of.  Paper profiles are necessary because papers are
different, but, assuming some sort of standard, some papers are more
different than others.  In my articles on BO printing I recommend
using EEM as a standard proofing paper.  It looks great, has excellent
Dmax, contrast, etc.  It's cheap, readily available in stores, and is
widely used. It's the closest thing to a standard that exists.  Great
stuff, only it's not cotton and turns yellow, so we need something
else for final prints.

In the articles I recommend using Photo Rag (PR) because it has the
same density and contrast as EEM, and produces nearly identical prints
 (it also happens to have the best Dmax of any cotton paper and is
gorgeous stuff, so we get the best of both worlds and it's easy). 
It's probably the most popular cotton paper (also very expensive).  

Because PR is brighter than EEM, some prints look a bit weak and
require a slight darkening curve, usually no more than 2 or 3 RGB
units in the center.  This curve could be called a "PR profile", but
the problem is it can't be applied to every image.  Some need less,
some none at all.

I think this is because in BO prints the paper surface is a more
active part of the image than with full-ink systems (this is what
gives BO prints the luminance that so many people like).  Higher key
prints tend to need more adjustment because more of the brighter
surface is showing and it has a greater effect.

Lately I've been trying other cotton papers and have found a few that
give results comparable to PR (none have quite as much Dmax but they
are good).  However, some are similar to EEM and some are different
enough to need an adjustment curve to match the proof.  Some need a
simple darkening curve like PR, but some need an actual contrast
adjustment.

As I experiment further I'm discovering that, like with PR, not every
image needs the same curve.  So I can't create and save a curve for an
image on Premier Hot Press, for example, and expect it to work for
every image on that paper.

The approach I'm taking now is to put a final curve layer in an image
file and leave it there (or a temporary layer can be applied each
time).  The layer can be switched off when printing on EEM.  I also
keep notes on each image and I write down the plot points for the
curve used for a particular paper (these are usually simple curves
with 1 to 3 points).  If I also print the image on another paper I
write down those curve points.  Next time I want to print on a given
paper the plot points can easily be entered into the curve.

Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm