Off Topic
15 replies to this thread. Most Recent
Color Management
In an effort to get a firmer grip on color management for print work I’m finding I need some advice from the more experienced of you. Using AI (Illustrator) I’m finding that there are a lot of color-related options available, many of which I don’t fully understand. I realize there are probably many variables or requirements that determine the proper color settings from one doc or professional printer to the next, but - here’s the $64 question - is there a general rule of thumb that might help narrow some of the options a bit? Perhaps the default settings are fine, I don’t know. A very broad question, I know, but a little direction would be of great help.
For example:
Menu > Edit > Color Settings Settings - North America General Purpose 2 (Is this OK?) Working Spaces RGB - Adobe RGB (or sRGB?) CMYK - US Web Coated (SWOP) v2
Menu > Edit > Assign Profile - Is it preferable to use the Working profile or one of the defaults or not color manage?
Thanks,
Todd
What kind of printing do you intend to do? A CMYK color profile is most beneficial if the kind of printing you will be doing will use process colors (CMYK) in a Litho press. General desktop printing or small run digital printing will work with RGB profiles just fine.
There is often a color shift if you convert from RGB to CMYK or vise a versa so be careful to print a test proof before committing to a final print run in order to judge color correctness. A file created with CMYK profile for example when printed on RGB printer will have a washed out appearance.
Adobe’s sRGB is more or less regarded as the standard for RGB, but Apple’s RGB profile is slightly different and more related to monitor color than print color. US Wed Coated (SWOP) is pretty much generic for CMYK profile also.
Freeway Pro 5.5, i7 Macbook Pro 2.2 ghz 8gb ram, 2.3 ghz Dual Core MacPro 10gb ram
Primarily small run digital will be norm though I suppose a Litho job may pop up now and then.
You mention “Adobe’s sRGB”. In my list of profiles I see sRGB IEC61966-2.1 and Adobe RGB but not the one you mention. Did you mean Adobe RGB?
Thanks chuckamuck, that helps.
Todd
On Feb 5, 2009, at 10:14 PM, chuckamuck wrote:
What kind of printing do you intend to do? A CMYK color profile is most beneficial if the kind of printing you will be doing will use process colors (CMYK) in a Litho press. General desktop printing or small run digital printing will work with RGB profiles just fine.
Adobe’s sRGB is more or less regarded as the standard for RGB, but Apple’s RGB profile is slightly different and more related to monitor color than print color. US Wed Coated (SWOP) is pretty much generic for CMYK profile also.
On 6 Feb 2009, at 15:33, Todd wrote:
You mention “Adobe’s sRGB”. In my list of profiles I see sRGB IEC61966-2.1 and Adobe RGB but not the one you mention. Did you mean Adobe RGB?
I think it was a slip of the keyboard.
I’ve sort of adopted Adobe RGB as the base workflow profile for my print work. I also calibrate my screen(s) with a hardware calibrator (Pantone Huey Pro in my case) so the software knows what to show me.
I use Adobe RGB as the default colour space for my DSLR, too. Anything that comes into Photoshop, Illustrator or InDesign without an embedded profile prompts the software to ask me if I want to leave it, or apply the default workflow profile. Once everything has the profile somewhere, it all works pretty seamlessly.
It’s changed so much since I started this game. I don’t think in CMYK any more, drawing in RGB images and illustrations, CMYK colours, Pantone spot colours changed to CMYK on the fly, and all flattened to a known PDF profile at the end.
The hardest part is ensuring everything you use is singing from the same profile. Once you’ve got that sorted, it’s pretty easy to use.
It’s so much simpler than when I began, darn it, over twenty years ago.
Heather
^-^
http://gallery.me.com/heatherkay#gallery A growing collection of personal pixels
http://homepage.mac.com/heatherkay/Model%20Photography%20Portfolio/ Scale models I have known
¬_¬
I’d like the chance to prove that money doesn’t make me happy. - S. Milligan.
Thanks Heather,
It’s all starting to gel a little bit. I do wonder though, if I’m given a file with a different (or custom) embedded profile from what I’m using (say, Adobe RGB) is it always best to change it to my default?
On Feb 6, 2009, at 10:15 AM, Heather Kavanagh wrote:
I use Adobe RGB as the default colour space for my DSLR, too. Anything that comes into Photoshop, Illustrator or InDesign without an embedded profile prompts the software to ask me if I want to leave it, or apply the default workflow profile. Once everything has the profile somewhere, it all works pretty seamlessl
On 6 Feb 2009, at 16:27, Todd wrote:
is it always best to change it to my default
I guess it depends on whether you’re going to be editing the file in any great way or not.
I will generally convert an incoming image to my preferred profile, I have to say.
Heather
^-^
http://gallery.me.com/heatherkay#gallery A growing collection of personal pixels
http://homepage.mac.com/heatherkay/Model%20Photography%20Portfolio/ Scale models I have known
¬_¬
I’d like the chance to prove that money doesn’t make me happy. - S. Milligan.
Adobe RGB (1998) is the best RGB colour space to use for general work, including scanning, digital photography and image manipulation and adjustment. It covers a broad part of the visible spectrum, and can be achieved by decent quality displays. The sRGB standard is more of a lowest-common-denominator colour space, one that covers the range of colour that you can reasonably expect to be achievable on the average bog-standard display - NOT on a high-quality display. (As I sometimes tell my students, the ‘s’ in sRGB is for ‘standard’, but there’s another word beginning with ‘s’ that could equally be used.)
My Photoshop image fine-tuning is done in Adobe RGB. Then, because browsers and browser plugins assume image content is sRGB (and hence produce particularly dull renderings of content that’s in a broader RGB colour space) I convert the profile to sRGB in Photoshop. (That’s Edit > Convert to Profile - NOT Edit > Assign Profile.) This gives me the best standard colour space for editing and then produces the best final results in sRGB once I’m done. Of course, when working for print I don’t convert to sRGB, ever.
Calibration is actual adjustment of the behaviour of a device, normally a display. The idea is to get the device working as best it can, then to profile it to measure just how well it performs.
The thing to remember about profiles is that they don’t change your image content, they just describe the characteristics of the device they are for…
A monitor profile describes the strengths and weaknesses of that monitor, and the colour management system adjusts the signal sent to that display to compensate.
A scanner profile describes the way the scanner’s results match or don’t match the original, so the colour management system knows what compensation should be used when dealing with something with that scanner profile.
A printer profile describes how well or otherwise the printer manages to do at rendering specific colours, shades and tones, so the colour management system can take that into account when print data is compiled and sent to the device.
You can use the profile of one output device to proof something using a different output device. For example, you can use a (high-quality) inkjet printer to proof the way work will look on a four-colour offset litho press. The caveat being that you need accurate profiles for both, and that if the proofing device can’t quite render the same tones/hues that the destination device can then the proof will be limited in those respects.
If you use CS3 or CS4 then select one main app to configure the colour settings - I suggest Photoshop as it has the widest range of controls - then save those, go to Adobe Bridge, and pick this as the suite-wide synchronised colour settings.
I don’t use Adobe’s generic colour settings; they are safe enough, but certainly not ideal for sheet-fed work on normal coated stock. My standard settings for regular print work and all photo manipulation, when I don’t have specific press profiles to work with, are as follows:
Working Spaces RGB: Adobe RGB (1998) CMYK: Coated FOGRA39 (ISO 12647-2:2004) Gray: Dot Gain 15% Spot: Dot Gain 15%
Color Management Policies RGB, CMYK and Gray: all Preserve Embedded Profiles
Description: “General-purpose colour settings for print. Adobe RGB and FOGRA39”
FOGRA39 is a reasonable fall-back standard for general offset litho work. It is a recognised European standard and a ratified ISO standard too. I recommend this over the slightly thin results that you can get from US Web Coasted (SWOP), the normal defaults. And whatever you do, don’t use Euroscale - that’s based on inks that haven’t been manufactured for years!
Remember, RGB colour can be brighter and more saturated than can be achieved in CMYK, but there are a few parts of the CMYK spectrum (notably pure 100% cyan) that can’t be precisely rendered in RGB. Colour conversion from RGB to CMYK should be done only when you know what standard to use (that’s the FOGRA39, US Web, US Sheetfed, Web Coated SWOP, etc., or you have a specific press profile). Going from RGB to CMYK throws away data that you can’t get back, so do your homework first - even if this means just picking a general standard that seems appropriate.
You can use an all-RGB workflow and have your colour converted to CMYK as late as possible in the prepress process. This ensures that your RGB colours are converted as appropriately as possible, but it also means that you have taken your hands off the wheel (as it were) before that all-important point. If you want to match precise CMYK colour values then you need to produce those yourself. So - in these cases, when working for print, specify colours in CMYK.
k (done ramblin’)
k (done ramblin’)
A digital color seminar in a nutshell. ;-)
Adobe RGB is the generic profile used most often, and probably most reliably. sRGB as Keith points out is lowest common (acceptable?) profile and relates to digital display. I didn’t bring up the calibration issue so as not to muddy the waters, but to accurately (as much as is possible anyway) judge color correctness from monitor to proof calibration is a must.
For CMYK, different areas of the globe standardize on different profiles based on the press and ink in use as Keith has intimated.
Freeway Pro 5.5, i7 Macbook Pro 2.2 ghz 8gb ram, 2.3 ghz Dual Core MacPro 10gb ram
A really outstanding explanation, thank you. Things are getting clearer all the time.
Questions:
In the Save Adobe PDF dialog there’s a picking list called Standard with several options like: None, PDF/X-3:2002 etc. I’ve been reading about some of these but how do you know when to use one instead of the None option? Is it something that the printer will tell you about if they require it?
Are there times when a printer will require you to use their own specific (custom?) profile and send it to you?
Todd
On Feb 6, 2009, at 11:32 AM, Keith Martin wrote:
Adobe RGB (1998) is the best RGB colour space to use for general work, including scanning, digital photography and image manipulation and adjustment. It covers a broad part of the visible spectrum, and can be achieved by decent quality displays. The sRGB standard is more of a lowest-common-denominator colour space, one that covers the range of colour that you can reasonably expect to be achievable on the average bog-standard display - NOT on a high-quality display. (As I sometimes tell my students, the ‘s’ in sRGB is for ‘standard’, but there’s another word beginning with ‘s’ that could equally be used.)
My Photoshop image fine-tuning is done in Adobe RGB. Then, because browsers and browser plugins assume image content is sRGB (and hence produce particularly dull renderings of content that’s in a broader RGB colour space) I convert the profile to sRGB in Photoshop. (That’s Edit > Convert to Profile - NOT Edit > Assign Profile.) This gives me the best standard colour space for editing and then produces the best final results in sRGB once I’m done. Of course, when working for print I don’t convert to sRGB, ever.
Calibration is actual adjustment of the behaviour of a device, normally a display. The idea is to get the device working as best it can, then to profile it to measure just how well it performs.
The thing to remember about profiles is that they don’t change your image content, they just describe the characteristics of the device they are for…
A monitor profile describes the strengths and weaknesses of that monitor, and the colour management system adjusts the signal sent to that display to compensate.
A scanner profile describes the way the scanner’s results match or don’t match the original, so the colour management system knows what compensation should be used when dealing with something with that scanner profile.
A printer profile describes how well or otherwise the printer manages to do at rendering specific colours, shades and tones, so the colour management system can take that into account when print data is compiled and sent to the device.
You can use the profile of one output device to proof something using a different output device. For example, you can use a (high- quality) inkjet printer to proof the way work will look on a four- colour offset litho press. The caveat being that you need accurate profiles for both, and that if the proofing device can’t quite render the same tones/hues that the destination device can then the proof will be limited in those respects.
If you use CS3 or CS4 then select one main app to configure the colour settings - I suggest Photoshop as it has the widest range of controls - then save those, go to Adobe Bridge, and pick this as the suite-wide synchronised colour settings.
I don’t use Adobe’s generic colour settings; they are safe enough, but certainly not ideal for sheet-fed work on normal coated stock. My standard settings for regular print work and all photo manipulation, when I don’t have specific press profiles to work with, are as follows:
Working Spaces RGB: Adobe RGB (1998) CMYK: Coated FOGRA39 (ISO 12647-2:2004) Gray: Dot Gain 15% Spot: Dot Gain 15%
Color Management Policies RGB, CMYK and Gray: all Preserve Embedded Profiles
Description: “General-purpose colour settings for print. Adobe RGB and FOGRA39”
FOGRA39 is a reasonable fall-back standard for general offset litho work. It is a recognised European standard and a ratified ISO standard too. I recommend this over the slightly thin results that you can get from US Web Coasted (SWOP), the normal defaults. And whatever you do, don’t use Euroscale - that’s based on inks that haven’t been manufactured for years!
Remember, RGB colour can be brighter and more saturated than can be achieved in CMYK, but there are a few parts of the CMYK spectrum (notably pure 100% cyan) that can’t be precisely rendered in RGB. Colour conversion from RGB to CMYK should be done only when you know what standard to use (that’s the FOGRA39, US Web, US Sheetfed, Web Coated SWOP, etc., or you have a specific press profile). Going from RGB to CMYK throws away data that you can’t get back, so do your homework first - even if this means just picking a general standard that seems appropriate.
You can use an all-RGB workflow and have your colour converted to CMYK as late as possible in the prepress process. This ensures that your RGB colours are converted as appropriately as possible, but it also means that you have taken your hands off the wheel (as it were) before that all-important point. If you want to match precise CMYK colour values then you need to produce those yourself. So - in these cases, when working for print, specify colours in CMYK.
k (done ramblin’)
In the Save Adobe PDF dialog there’s a picking list called Standard with several options like: None, PDF/X-3:2002 etc. I’ve been reading about some of these but how do you know when to use one instead of the None option? Is it something that the printer will tell you about if they require it?
Best practice is to ask the printer which version of PDF-X they prefer. Makes you look knowledgable too. ;-)
Are there times when a printer will require you to use their own specific (custom?) profile and send it to you?
That is possible, but you need to ask.
Freeway Pro 5.5, i7 Macbook Pro 2.2 ghz 8gb ram, 2.3 ghz Dual Core MacPro 10gb ram
Thank you very much chuckamuck, Heather and Keith.
Todd
On Feb 6, 2009, at 2:12 PM, chuckamuck wrote:
In the Save Adobe PDF dialog there’s a picking list called Standard with several options like: None, PDF/X-3:2002 etc. I’ve been reading about some of these but how do you know when to use one instead of the None option? Is it something that the printer will tell you about if they require it?
Best practice is to ask the printer which version of PDF-X they prefer. Makes you look knowledgable too. ;-)
Are there times when a printer will require you to use their own specific (custom?) profile and send it to you?
That is possible, but you need to ask.
Sometime around 6/2/09 (at 15:12 -0500) chuckamuck said:
Best practice is to ask the printer which version of PDF-X they prefer. Makes you look knowledgable too. ;-)
That’s true on both counts.
The different PDF/X options aren’t about making special new kinds of PDF, they are simply the names for sets of established PDF production standards that the print industry has agreed. Producing a PDF using a PDF-X standard means that it is absolutely guaranteed to be produced using an unambiguous list of settings.
From the Creative Suite 3 Integration book:
The PDF/X settings are ISO standards for graphic content exchange. The PDF/X standard was first established as PDF/X-1 in 1998, but it took a number of years before the standard became widely accepted. From 2001 there have been enhancements to the PDF-X standard, but all versions use relatively early versions of the PDF file format. Even the PDF/X-4:2007 [[and now PDF/X4 2008]] uses the PDF 1.4 format. PDF/X isn’t a new form of PDF document, instead it sets out an important series of benchmark settings that allow documents to be transferred without requiring further information. PDF/X provides a prepress-oriented set of standards for PDF documents to meet, including full embedding of fonts and high-resolution image data, inclusion of bleed, trim and art-box definitions, embedded information on trapping, and more. The PDF/X-1 standards convert colors to the destination color space, set as the CMYK working space as defined in the Color Settings in the origination program, whereas the newer PDF-X specifications perform no color conversion at all but set the declared output intent to the CMYK working space. If a printer or prepress company asks for a particular PDF-X standard, this is to ensure that the PDF artwork they receive will be prepared to a known, output-ready set of standards. This doesn’t guarantee absolutely no problems during production and it is not the same thing as preflighting a document before preparing the PDF, but it does eliminate most of the things that can cause difficulties and inonsistent output.
And also from that book:
PDF/X-1a:2001 All color is converted to CMYK using the destination profile, and transparency is flattened at high resolution. The result is a standards-based PDF that will be handled with confidence by most prepress operators. P DF/X-3:2002 […] the output intent profile is set to the one defined in the Color Settings controls but document colors aren’t converted at all. This allows for color-managed workflows and color spaces other than CMYK, including spot colors, while still conforming to PDF/X standards. Transparency is flattened at high resolution.
PDF/X-4:2007 […] As well as the more flexible approach to color offered by PDF/X-3, it includes support for transparency and layers in the PDF document, so the Transparency Flattener is disabled.
Producing to a PDF/X standard this doesn’t guarantee that it will print perfectly, just like a car’s MOT (UK Ministry of Transport roadworthiness) test certificate doesn’t mean the engine isn’t clapped out. But it can certainly help avoid the majority of pitfalls, and preflighting will help avoid most of the rest.
Are there times when a printer will require you to use their own specific (custom?) profile and send it to you?
Perhaps. As Chuckamuck says, ask.
Realistically speaking, a well-run press should be adjusted (calibrated) to print pretty precisely and to basic standards, so printing on a standard stock will produce results that fall within certain tight parameters. But it is still not a bad idea at all to use a profile if it is available. Not least because different paper stock will produce different kinds of results - so a profile for a particular press on a particular stock will get your colour management system on board and helping to keep things on track right through to the final print.
(BTW, if you make and rely on profiles for an inkjet printer it is important to make profiles for each different kind of paper stock you use, and to do it again if you change your ink cartridge brand. Either of these things will affect the output, rendering previous profiles inaccurate.)
k
Tremendous information Keith, thanks.
That explains the sometimes large inconsistencies I’ve seen when using different stock. Surprising how the output can vary so greatly. Well, surprising to me. ; )
Todd
On Feb 6, 2009, at 5:57 PM, Keith Martin wrote:
(BTW, if you make and rely on profiles for an inkjet printer it is important to make profiles for each different kind of paper stock you use, and to do it again if you change your ink cartridge brand. Either of these things will affect the output, rendering previous profiles inaccurate.)
Is the “X” in PDF/X pronounced “ex” or
Or X as in kiss? ;-) No, it is “ex” as in “Pee Dee Eff Ex”.
k
Many printers still ask for PDF/X-1a:2001 - or convert to this, because of issues with transparency
On 6 Feb 2009, at 11:57 pm, Keith Martin wrote:
PDF/X-1a:2001 All color is converted to CMYK using the destination profile, and transparency is flattened at high resolution. The result is a standards-based PDF that will be handled with confidence by most prepress operators.
David Owen :: Freeway Friendly Web Hosting and Domains http://www.ineedwebhosting.co.uk
www.ineedwebhosting.co.uk | Twitter Offers and Web Design News
Freeway Friendly web hosting and Domain Names. (Create an account it’s Free!)
PrintlineAdvertising.co.uk | The Printline Advertising Blog
Print Design, Digital and Litho Printers, Promotional Merchandise and Corporate Gifts.
