Digital BW, The Print

Folks,

I am now writing an article on making digital negatives utilizing  
Epson 1280 and Epson 10000 printers.  I promised everyone 
here that I would update the list once I was a bit further along.

Well, here it is.

I am now making digital negatives and printing them in platinum 
and silver. I ran into a major issue with what I was calling "digital 
grain",  That is my platinum prints showed a noted increase in 
grain. Not really a problem when making 24"x24" negatives, but 
a real problem with small 5x7 or 8x10 prints.

Finally I linked the problem with the Epson driver. With the 
combination of inks that I find works the best, the Epson dither 
would create digital artifacts (mabe not the right term), or 
perhaps optical artifacts that manisfested themselves as what 
appeared to be increased grain.

I finally solved this problem and also the problem of smooth 
tones in sky areas by utilizing the ImagePrint RIP. I will go into all 
of the detail and my procedure in my article. The neatest and 
most exciting aspect for is that I do not have to use a restrainer 
(contrast agent) in my platinum coating. Contrast agent 
degrades the platinum image by clumping the grain into ugly 
nasy groupings. In my process, it is no longer necessary  to use 
Potassium Chlorate or any of the dichromates to obtain contrast 
control.

Another issue with which I was concerned is that of fading of the 
negative when exposed to very strong UV light. My UV exposure 
unit utilizes 12 40watt VHO UV tubes. My contact print times are 
running 150-220 seconds. I was concerned that after perhaps 6-
10 prints the density of the digital negative would be reduced 
enough that the print times would be affected. I am finding that 
with the dyes that I am using (dyes seem to make smoother 
digital negatives in my experience) seem to initially shift toward 
red under the strong UV light. Once exposed the first time, they 
actually gain a slight amount of density and them maintain their 
density for subsequent printings. once my testing is finished, i 
will post the sensitometry to support this position. As many of 
you know, platinum printing requires significantly more density 
than does the silver process. Since the dyes tend to shift toward 
red after exposure, the reddish color acts to build density.

I will keep everyone updated.

Mike