Digital BW, The Print

This one is especially interesting, there is concern about the way the  
printing company manage the flow
as the files are swinging from yellow to blue???

> --- 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.
>
>
> 



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