December 2016 - colorsync-users

Re: Colorsync-users Digest, Vol 13, Issue 169
by Péter Nagy 21 Dec '16

21 Dec '16

Hi Jorge, the problem you described is a problem for many people. Without high-end tools your first choice is to do a group of trial-and-error experiments, using all the options in your version of Acrobat. I assume you've done that already. If you can access the original material (the InDesign doc and all the linked images), you can try exporting directly to sRGB. If your input is strictly PDF, then the last resort is a professional tool like Callas pdfToolbox. Using that software you have access to sophiscticated (albeit circumvent) ways to map any kind of black to K. They have a free 14 days trial for first time downloads so you can play around with the options until you find a solution. Kind regards, Péter Nagy Colorcom Media, Budapest On Tue, 12/20/2016 09:00 PM, colorsync-users-request(a)lists.apple.com wrote: > Send Colorsync-users mailing list submissions to > colorsync-users(a)lists.apple.com > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.apple.com/mailman/listinfo/colorsync-users > or, via email, send a message with subject or body 'help' to > colorsync-users-request(a)lists.apple.com > > You can reach the person managing the list at > colorsync-users-owner(a)lists.apple.com > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Colorsync-users digest..." > > > Today's Topics: > > 1. Acrobat color conversion: DeviceGray vs DeviceN "Black" CMYK > (0, 0, 0, 1) (Jorge .) > 2. Re: Acrobat color conversion: DeviceGray vs DeviceN "Black" > CMYK (0,0,0,1) (Jorge .) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 20 Dec 2016 11:21:09 +0100 > From: "Jorge ." <chocolate.camera(a)gmail.com> > To: "'colorsync-users?lists.apple.com' List" > <colorsync-users(a)lists.apple.com> > Subject: Acrobat color conversion: DeviceGray vs DeviceN "Black" CMYK > (0, 0, 0, 1) > Message-ID: > <CANTj5d_8OPMObAkuT+4aMOdejWy=zW_skJR6nZW-p_47fZa9Mw(a)mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > When exporting to PDF with InDesign CC 2015.4 using the default PDF/X-4 > preset, grayscale images filled with the default solid Black swatch (100K, > Uncoated FOGRA29) are exported as DeviceGray, unless somewhere in the > layout there also exist a partially transparency vector object using the > same black, in which case those grayscale images are exported as filled > with DeviceN: "Black" CMYK (0,0,0,1) instead. > > Is there a way to control this, or a reason for it? Is there any way, with > Acrobat or a free command-line tool, to replace the DeviceN: "Black" CMYK > (0,0,0,1) black of grayscale images with DeviceGray? > > Why do I care: > > When using Acrobat DC 2015 to convert all colors to sRGB (Tools > Print > Production > Convert Colors > Convert colors to output intent: sRGB), > Acrobat maps the black of vector objects filled with the default solid > black (100K) to black RGB (0,0,0), and does the same with the black of > DeviceGray grayscale images. All blacks in those PDFs consistently become > 0,0,0 RGB. > > But if grayscale images were exported as filled with DeviceN: "Black" CMYK > (0,0,0,1), their black is converted to RGB muddy gray, and therefore color > conversions of layouts containing both vector objects and grayscale images, > both filled with solid black, produces inconsistent RGB blacks. > > Just to clear up: my purpose is not obtaining color-accurate RGB > conversions of CMYK solid blacks, but getting RGB blacks that are pleasant > for screen viewing, i.e. 0,0,0 RGB. That, I already get from 100K-filled > vector objects when converting colors as described above, but not from > grayscale images filled with DeviceN: "Black" CMYK (0,0,0,1). I do > understand CMYK solid blacks do not match in fact their color space's black > point, and therefore that a color-accurate conversion should produce RGB > muddy grays, and I can indeed also get Acrobat to do that for all 100K, be > them from vector objects and from grayscale images filled with DeviceN: > "Black" CMYK (0,0,0,1), by using Acrobat's "Conversion Attributes" color > conversion options instead of "Convert Colors To Output Intent". But what I > want them to be is consitent 0,0,0 RGB. > > > ------------------------------ > > Message: 2 > Date: Tue, 20 Dec 2016 11:30:33 +0100 > From: "Jorge ." <chocolate.camera(a)gmail.com> > To: "'colorsync-users?lists.apple.com' List" > <colorsync-users(a)lists.apple.com> > Subject: Re: Acrobat color conversion: DeviceGray vs DeviceN "Black" > CMYK (0,0,0,1) > Message-ID: > <CANTj5d-EGRnZraBMa6tVXjkxHrBaF2=0hoF0zoLeHizi+xS4kw(a)mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > Here is a set of files illustrating the issue: https://cl.ly/1a1v0m0v2127 > > • `image.tif` is a 100% black grayscale image. > > • `DeviceGray.indd` is an InDesign document (idml also provided) containing > the image plus an opaque vector object filled with the default 100K Black. > Exporting using the preset PDF/X-4 generates `DeviceGray.pdf` which uses > DeviceGray for the grayscale image. > > • `DeviceN.indd` is an identical InDesign document except for the fact that > the vector object is given partial transparency. Exporting using the same > PDF preset generates `DeviceN.pdf` which uses DeviceN: "Black" CMYK > (0,0,0,1) for the grayscale image instead of DeviceGray. > > Using Acrobat to convert colors to sRGB (Tools > Print Production > Convert > Colors > Convert colors to output intent: sRGB) provides consisted RGB > 0,0,0 blacks for both the vector object and the grayscale image in > `DeviceGray.pdf` but not in `DeviceN.pdf`. > > On Tue, Dec 20, 2016 at 11:21 AM, Jorge . <chocolate.camera(a)gmail.com> > wrote: > > > When exporting to PDF with InDesign CC 2015.4 using the default PDF/X-4 > > preset, grayscale images filled with the default solid Black swatch (100K, > > Uncoated FOGRA29) are exported as DeviceGray, unless somewhere in the > > layout there also exist a partially transparency vector object using the > > same black, in which case those grayscale images are exported as filled > > with DeviceN: "Black" CMYK (0,0,0,1) instead. > > > > Is there a way to control this, or a reason for it? Is there any way, with > > Acrobat or a free command-line tool, to replace the DeviceN: "Black" CMYK > > (0,0,0,1) black of grayscale images with DeviceGray? > > > > Why do I care: > > > > When using Acrobat DC 2015 to convert all colors to sRGB (Tools > Print > > Production > Convert Colors > Convert colors to output intent: sRGB), > > Acrobat maps the black of vector objects filled with the default solid > > black (100K) to black RGB (0,0,0), and does the same with the black of > > DeviceGray grayscale images. All blacks in those PDFs consistently become > > 0,0,0 RGB. > > > > But if grayscale images were exported as filled with DeviceN: "Black" CMYK > > (0,0,0,1), their black is converted to RGB muddy gray, and therefore color > > conversions of layouts containing both vector objects and grayscale images, > > both filled with solid black, produces inconsistent RGB blacks. > > > > Just to clear up: my purpose is not obtaining color-accurate RGB > > conversions of CMYK solid blacks, but getting RGB blacks that are pleasant > > for screen viewing, i.e. 0,0,0 RGB. That, I already get from 100K-filled > > vector objects when converting colors as described above, but not from > > grayscale images filled with DeviceN: "Black" CMYK (0,0,0,1). I do > > understand CMYK solid blacks do not match in fact their color space's black > > point, and therefore that a color-accurate conversion should produce RGB > > muddy grays, and I can indeed also get Acrobat to do that for all 100K, be > > them from vector objects and from grayscale images filled with DeviceN: > > "Black" CMYK (0,0,0,1), by using Acrobat's "Conversion Attributes" color > > conversion options instead of "Convert Colors To Output Intent". But what I > > want them to be is consitent 0,0,0 RGB. > > > > > ------------------------------ > > _______________________________________________ > Colorsync-users mailing list > Colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users > > End of Colorsync-users Digest, Vol 13, Issue 169 > ************************************************ >

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Acrobat color conversion: DeviceGray vs DeviceN "Black" CMYK (0, 0, 0, 1)
by Jorge . 20 Dec '16

20 Dec '16

When exporting to PDF with InDesign CC 2015.4 using the default PDF/X-4 preset, grayscale images filled with the default solid Black swatch (100K, Uncoated FOGRA29) are exported as DeviceGray, unless somewhere in the layout there also exist a partially transparency vector object using the same black, in which case those grayscale images are exported as filled with DeviceN: "Black" CMYK (0,0,0,1) instead. Is there a way to control this, or a reason for it? Is there any way, with Acrobat or a free command-line tool, to replace the DeviceN: "Black" CMYK (0,0,0,1) black of grayscale images with DeviceGray? Why do I care: When using Acrobat DC 2015 to convert all colors to sRGB (Tools > Print Production > Convert Colors > Convert colors to output intent: sRGB), Acrobat maps the black of vector objects filled with the default solid black (100K) to black RGB (0,0,0), and does the same with the black of DeviceGray grayscale images. All blacks in those PDFs consistently become 0,0,0 RGB. But if grayscale images were exported as filled with DeviceN: "Black" CMYK (0,0,0,1), their black is converted to RGB muddy gray, and therefore color conversions of layouts containing both vector objects and grayscale images, both filled with solid black, produces inconsistent RGB blacks. Just to clear up: my purpose is not obtaining color-accurate RGB conversions of CMYK solid blacks, but getting RGB blacks that are pleasant for screen viewing, i.e. 0,0,0 RGB. That, I already get from 100K-filled vector objects when converting colors as described above, but not from grayscale images filled with DeviceN: "Black" CMYK (0,0,0,1). I do understand CMYK solid blacks do not match in fact their color space's black point, and therefore that a color-accurate conversion should produce RGB muddy grays, and I can indeed also get Acrobat to do that for all 100K, be them from vector objects and from grayscale images filled with DeviceN: "Black" CMYK (0,0,0,1), by using Acrobat's "Conversion Attributes" color conversion options instead of "Convert Colors To Output Intent". But what I want them to be is consitent 0,0,0 RGB.

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profiling back-printed plexiglass?
by Randy Norian 12 Dec '16

12 Dec '16

Good afternoon! It’s quite likely that this has been covered before, however, I have to ask. We are attempting to print high quality images on the back face of clear plexiglass, with a white ink layer behind the image. The print engine in question is a Rastek H625 (by EFI) UV-cured inkjet. While I can color manage paper prints with this device, the backside-plexiglass printing has me stymied. The images are extremely bright and overly-contrasty, to the point of being unacceptable, especially as companion pieces to other latex work we’re doing. I thought I’d just characterize the output on the plexiglass, however my ES-2000 won’t read the swatches through the plexiglass, for whatever reason — it simply faults out. I’m using EFI color profiler suite 4.6. Have any of you faced the same issue? Any advice on how to go about color managing this sort of printing? I know I have to figure out how to read these swatches, but beyond that, are there any caveats for working with "back side of glass” printing? Many thanks- Randy Norian

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In-browser monitor profiling?
by Jeff Nova 07 Dec '16

07 Dec '16

Remember how e-Color used to permit users to calibrate and profile their monitors in-browser, and stored the result in its extension? Well, that company is no more, and the tech seems to have been laid to rest. Is there any solution for color management on the web that is on the monitor side? I know color management has grown incredibly with browser support and OS support - only Chrome on Android and Android specifically are still not color managed - but that doesn't mean we can count on a good monitor profile. Anyone know of a solution? Best, Jeff -- Jeff NovaChief Executive OfficerColorhythm jnova(a)colorhythm.comMain: +1 415-399-9921Mobile: +1 510-710-9590Fax: +1 415-399-9928 1015 Battery Street, Suite CSan Francisco CA 94111http://colorhythm.com This electronic mail and the documents accompanying it are considered trade secret, confidential and/or proprietary by Colorhythm LLC. This information is intended for use by the individual or entity to whom this e-mail is addressed. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited.

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