Frank - I use a lab that has a Fuji Pictrography printer and a LightJet
printer. When I want b&w output, I typically work the file in Photoshop as
a grayscale image, but then convert at the end to RGB which those machines
want. I have had the lab run some tests for me, so I know what to do to
tweak the files to get them the tone (or the lack of tone) that I want. I
would encourage you to do the same. My lab provided me with profiles for
the machines (and the different papers that they run in them) so that I can
soft-proof in Photoshop to see what the images will look like in their
system.
Stephen Petegorsky
petegorsky@...
web site - www.spphoto.com