Datacolor User to User Support Group.

--- In colorvision_group@yahoogroups.com, Myron Gochnauer <goch@...> wrote:
>
> I'd like to hear comments from any of you using PFP 2.0 to profile  
> black and white printers.
> 
> My biggest headache with digital printing of black and white images  
> is the tendency for very dark tones to look posterized (paint-by- 
> numbers look) instead of showing subtle gradations.  This is  
> especially problematic with matte papers.
> 
> I am now using MIS UT3D inks on an Epson 2200, and trying to generate  
> profiles for Epson EM, Moaba's Kayenta, Breathing Colour's Sterling  
> Rag, and Kirkland glossy. So far nothing looks as good as the simple  
> EZ system MIS sells for the Epson C86 (which just lets the printer  
> think it is printing colour), or the HP system that had a special  
> black cartridge for printing B&W images.
> 
> I haven't begun experimenting with PFP 2.0's adjustments yet. If you  
> have experimented, can you give me any direction?
> 
> I've been printing "silver" for thirty some years, so my expectations  
> and strategies are suitably skewed.

Are you getting posterization with all of the papers?  I have profiled EEM, Premier Art Hot 
Press205, Ilford Smooth pearl, Crane Silver Rag and Epson Premium Glossy as well as 
some others I've dismissed, all with the UT3D and nothing has come out posterized except 
for a Crane print that I had split toned and pushed the warm highlights to an extreme to 
see what would happen, and even there the posterization was in the high end of the mid-
tones right where the split toning was ending.

A couple of things I found along the way if they might apply:  I've taken to reading all 
papers with an additional sheet of the same paper undeneath.  I was getting a lot of weird 
readings when trying to graph curve changes to 21 step ramps ala Paul Roark and I found 
two variables: the paper being too thin (use of the underlying second sheet is mentioned 
in the PFP help as necesary for thin papers but I found variations in all the papers I was 
using, the second was too aggressive use of a heat gun to dry prints before measuring.  
The change couldn't be seen by my naked eye but I could measure up to 3 L*a*b* points 
difference in paper white In sheets where I had or had not used the heat gun between 
different iterations so i assume the inked areas were off at least that amount as well.

Do you feel comfortable that your monitor would expose any posterization if it was in the 
image before printing?  I know I can push processes that are not visible in my laptop lcd 
but are visible in my desktop monitor.

Are you using Photo Black with glossies and Eboni with the mattes.  PFP doesn't have the 
ability to hold back the Eboni and double up the dark gray like Paul's curve method (as far 
as I know) so the use of Eboni on glossy papers will definately give a harsh gloss 
differential in the pure blacks and the ink will come off on your fingers as well.

Can you print a 21 step ramp through your profile and then read it with your spectro to 
see if you get good sharp step differences at the dark end of the ramp.?  And is the ramp 
going consistently in the same direction?

I will be profiling all of my papers on another printer of mine this week using the UT3D  I'll 
keep an eye out for anything that might tend toward posterization and let you know. 

 Robert