Digital BW, The Print

> Todd, I don't mean to butt in, but why even fool with it? Why not
> simply have a workflow from scan to print that leaves the
> file in the same gamma throughout? Between editing your scan, and
> doing whatever separation methods you use, enough
> potential bit lose is occurring.
> I haven't been following the thread, so maybe I missed something.
> Tyler

Hi Tyler,
The only problem is that the only way you can do that is to find the gamma
of the printer/ink/paper and stay in that space forever.  If you change any
part of that you have to adjust gamma anyway.  So my strategy has been to
keep to a standard grayscale working space for all editing and convert to
the printer's gamma at print time.  Since I am using a softproof process I
stick with a standard gamma space for the grayscale editing, convert to RGB
(of the same gamma), and then separate the channels with an RGB curve using
the quadtone preview to match the tonal range of original grayscale.  In
other words, since I don't use a final gamma move in the final print process
since I build it into the RGB curve.  Then my RGB curve is saved for the
particular ink and paper combination with the file (turn it on and off at
print time).  Same as a last minute gamma change in the suggested process
but my RGB curve and gamma change are all done together.

This is exactly the same set of options you have with color printing -- scan
and edit in a CMYK print space and archive in that very precise space, or
scan and edit in a broader RGB space and have greater flexibility for output
-- with a profile applied at output time taking the file into the printer
space.  In the grayscale case the output profile has been replaced with a
custom gamma version of the RGB space (which replaces the typical custom dot
area curve which can't be used in RGB processes).  Both are good options
depending on how you want to archive the file.

Not sure which standard grayscale space is really the best for most printers
- or for most monitors, but Blatner and Fraser recommend 2.2 for RGB mode
for perceptual uniformity in editing and since I am going through RGB space
I use a gamma 2.2 grayscale working space to edit.  I could be totally wrong
on that choice though.  Some radical folks have suggested that a 1.0 gamma
would be the best working space - others swear by 1.8 since it is nearer to
most printer's natural print space.  But since there are many paper types
there will always have to be some way to get the file into a precise printer
space - even if just to compensate for small dot gain changes and (if you
use an RGB grayscale file with no profile) the only quick way to do that is
with a custom RGB space at print time.   The best way to do that is with a
custom RGB profile and a softproof (which holds true with either grayscale
printed to CMYK inks or to quad inks) but the original process under
discussion didn't use one so this RGB gamma tweak at print time was the
suggested alternative.

Dan