Digital BW, The Print

I did some two-pass printing years ago: one pass on an 1160 with MIS
quadtones and another on a 1200 with color. My purpose was not to
improve darks, it was to integrate color with the smoothness of
quadtone B&W and to handle each part separately.

I found that, by using 1 pixel "L" shaped corner markers and keeping
the image well away from the leading edge with the markers that about
1 out of 4 print passes would align both marks and the print would
align pretty well - well enough that I was able in one test to put a
colored object exactly back into the B&W area is was previously cut
out of, with no white border showing and no apparent overlap. It was
very tedious, though, so I went to other methods for minimizing the
need for such accuracy.

The two printers did not align horizontally, so I had to put a shim in
one to make up the difference, but even so, the paper did not always
align perfectly no matter how much care I took in guiding it into the
printer.

I put the corner marks on the leading edge of the image file (sized
for the paper, with the image area having a large border of blank
paper, especially at the leading edge), so that I could watch them
being printed during the start of the second pass and just shut off
the printer and eject the paper, if they didn't align during that
pass. As I said, about 1 out of 4 passes they did align and the whole
print then would be aligned.

I wonder, though, if multiple coatings of black ink really would make
enough difference to make this process worthwhile: would you run into
the law of diminishing returns? I'll take a look at the Blacklock
article as soon as I get a chance.

Frank


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Djon"
<westsidemaurice@y...> wrote:
> 
> I mistakenly buried this idea in an earlier post...
> 
> In View Camera Magazine ( www.viewcamera.com ) Craig Blacklock
> explains "double-pass quadtone printing." Beautiful prints of nudes
> and nature.
> 
> I wonder if it will work on common 2200 and similar printers using OEM
> pigments?
> 
> I've started playing with the idea...using test photos, my 2200 places
> dots well within 1mm of where they belong on 9" test prints...maybe
> far more accurately than that...no halos showing out-of-register....
> 
> ...for example a low contrast green pass and a very high contrast
> black pass from a B&W negative I've made an accurately registered
> two-color silkscreen-style image ...incredibly precise considering
> it's a totally unmodified printer...
> 
> If this can be managed with subtlety in a common desktop printer like
> 2200, using Photoshop on conventional images it should increase Dmax
> tremendously and make these printers much more impressive.
> 
> Has anybody made this work?