Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, C D Tobie
<CDTobie@...> wrote:
>
> 
> On Feb 23, 2009, at 10:13 AM, d.burges wrote:
> 
> > Hi, Does anyone have an answer to obtaining neutral tone B+W images
> > when printing as a CMYK file. I'm a photographer in the UK putting
> > together a 62 page photobook for a client who wants the book in B+W,
> > the company which produce the books for me need  pdf files created in
> > photoshop coverted to CMYK as they print on a commercial printing  
> > press,
> > I've just had the books back and many of the pages have printed with
> > slightly differing hues, mainly yellow, some blue. Having read many
> > posts it would seem it is very hard to obtain neutral tones due to the
> > difficulty of mixing the CMY inks to produce neutral B+W, however I'm
> > hoping there is an answer out there somewhere! David
> 
> Color management will typically improve results, but if similarly  
> prepared files are coming out warm in some pages and cool on others,  
> than it would appear that the presses are not being run in a color  
> managed manner, or to tight enough standards to get consistent  
> results. The simple way to assure that files don't get color casts is  
> to create black-channel-only separations, where the entire image is  
> printed with only black ink, no colored inks blended in. This does not  
> allow control of the tone (whatever gray the black ink produces is  
> what you get) and may result in less smooth images, as there is only  
> one ink being used, but if your current results are unacceptable, it  
> might be an improvement.
> 


I would tend to agree here. Since the color casts vary, you might need
a better printing company or to change the way you do things with the
press. The heavy GCR is a step in the right direction, but as
mentioned above you might need to convert everything into the black
plate to get really neutral prints on a press that swings from yellow
to blue.

Instead of fighting the color issues, would it make sense to go with a
duotone? That way you might be able to control the color cast so that
all the pages were at least the same/similar color. It should improve
the apparent resolution in the lighter tones too. Maybe a tritone with
one color in the highlights and another in the dark tones.

One question also comes to mind... Is it really on a plate press, or
is it on a digital electrophotographic "press"? A lot of the
electrophotographic systems get put on the cheap end when the company
doesn't buy the good color managed RIP to drive them, or they don't
invest in color management tools and techniques to keep them neutral.

Definitely find out what the maximum ink load is for this machine with
your preferred paper. You might even ask them for the lab values of
each ink, and the secondaries so that you can build the proper CMYK
set up into Photoshop. You never know, they might actually know the
answer to that question.