Re: PS CMYK Conversions
Re: PS CMYK Conversions
- Subject: Re: PS CMYK Conversions
- From: sfprintservices <email@hidden>
- Date: Thu, 21 Aug 2008 20:45:14 -0700
- Thread-topic: PS CMYK Conversions
Hi,
This has been an interesting thread, lots of good info. I apologize for
hi-jacking it. I wanted to respond to some points and see if anyone has
anymore input. More than likely everyone is getting real tired of this by
now.
Graeme Gill wrote:
> What sort of question is that ? You embed the profile corresponding
> to the color space the CMYK is in ! That's the whole point of
> embedded profiles, they label the (otherwise) mystery meat device
> colorspace.
>
> You can't expect one CMYK file to target any old CMYK device
> and get predictable color out of it, you need to convert to
> the specific colorspace of the device for this to work well.
> That's the heart of modern color management.
As I pointed out earlier 90% of the time we do not have any information
about the press running the job. The file could be printed on a digital
press, an inkjet, Web offset, sheetfed, we hardly ever know.
Large multinational corps want their brand images to be reproduced where
they desire, when they desire and not to be told by the designers how to do
it.
Robert Rock wrote:
> all with the goal of maximizing the amount of
> printable colors we can squeeze out of the printer.
Many brands have their own corporate spot colors which are used to extend
the gamut of color presented to the client.
> Safer, yes. But for the geek in all of us that likes to push to the
> limits, it's just not exciting.
As long as the client is happy with it that's exciting enough.
> Most printers I know will set their RIP to ignore embedded profiles of any
> kind. In commercial and publications printing, unless a client specifically
> requests some sort of press-independent workflow, no one will touch the CMYK
> values that come in the door -- no one, it is just too risky.
In that case, why embed profiles in the CMYK files? Are printers going to
follow the Adobe "safe color workflow", honor the numbers and ignore
embedded profiles before converting to their press space? If we create and
save files in the SWOP v2 color space why would those numbers not be
honored?
RGB files are easier to handle. Photoshop files are left in RGB unless a
client requests all files to be in CMYK. Adobe RGB 1998 is large enough for
us. CMYK files are assembled with the linked RGB images. Files destined for
the Web are created in, or converted to sRGB.
Mike Strickler wrote:
> My sense from all of this is that
> what some people want to do is just select Mode: CMYK and be done
> with it. Thus the concern over the Photoshop default profiles (which
> nonetheless could be updated).
Actually, the concern is over Illustrator and InDesign default color
settings. I would prefer not to convert Photoshop images to CMYK.
> Without some editing this will not compress nicely into the press gamut.
> Maybe we should also discuss when, where and by whom this work should be done,
If the files need to be re-purposed further than the Adobe defaults of SWOP
v2 and Adobe RGB 1998 then the conversions should be done by someone with
more info about the final output.
> and why so many printers are still asking for CMYK images from their
> customers...
Curtis Lea wrote:
> Having their customers throttle back the colour themselves and thereby
> reduce their expectations takes a lot of weight off their shoulders
> too. At least CMYK gives them the opportunity to improve on what the customers
> submit.
Dick Busher wrote:
> I have worked with a few small print shops that do not have the
> experience to provide cmyk seps, nor the equipment to provide color
> managed proofs or even "internally color managed" proofs. They must
> have cmyk files and color managed proofs to get anything reasonable
> as output.
>
> And many print shops that do have those capabilities find that the
> customers are not willing to pay for those services anymore.
> printers are often supplied with a mix of rgb tiffs, rgb jpgs, cmyk
> files with or without tags and converted for who knows what output
> device; plus proofs generated god knows how!
Rich Apollo wrote:
> Well, there are a couple of reasons:
>
> 1) Printing happens in CMYK, not RGB. It is/was more efficient for us in the
> print world to have the images all ready in CMYK.
>
> 2) You end up mixing color modes. You've got images in RGB, there is black
> text throughout, maybe spot colors... Mixed color pieces are much more
> difficult to deal with.
>
> 3) PDF workflow. Take the mixed color bag, roll it into a PDF and the
> complexities compound.
>
> 4) There's the question of limited liability. If/when they don't like the
> print, folks are quick to point a finger. If we in prepress haven't done
> anything to the files then it's easier for us (and the whole company) to avoid
> blame.
>From reading this it seems printers would prefer CMYK files. Make them as
simple as possible, don't create anything that can't be converted to the
lowest common denominator (SWOP v2). If that gamut is too small use spot
colors and pay for the extra ink.
When Adobe updates their default pre-sets the lowest common denominator may
move up a notch or two. I am not counting on this happening in CS4.
Maybe Adobe will update faster now that the Ghent workgroup is recommending
the use of the updated SWOP and GRACoL profiles in PDF/X-4:
http://www.gwg.org/colormanagement.phtml
Mike Strickler wrote:
> It is far better
> to manage expectations through education and certified proofs that
> show the customers what they can expect on an IDEAL 4-color press of
> the same type as specified (e.g., GRACoL, Fogra, etc.)
It would be even better if the design house had this capability on-site and
could manage the expectations from conception to implementation and then
could depend on reproducing those certified proofs in various locations over
time.
Mike Strickler wrote:
> 2, 3, 4. It still makes more sense to insist all vector content be in device
> color, especially considering that spots are often part of the
> original specification. But there should be little problem with CMYK + spot
> documents containing placed RGB images, as log as you have the InDesign or
> Quark document and all the linked images to go in and work on. Then just
> update the links.
No argument.
Thanks,
Gary Scott
Landor Associates
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