Colour Management for Print – Concepts and basics
In a world of largely digital workflow Colour Management provides the basis for meaningful comparison between images viewed on screen (and indeed between different screens) and then reproduced in print. Within design and content creation responses to a mention of the concept can, in my experience, extend from ‘What’s that?’ to a belief it’s entirely the responsibility of the printer to reproduce colour images, as the client would see it, accurately.
The printing press is a wonderful piece of technology and engineering but ultimately it’s ability to change the printed result is limited to increasing or reducing CMYK ink levels. The scope for design and pre-press to influence what the press can give you is, however, enormous and work on that starts way before a printer gets involved, with the handling and preparation of image and design files. Good colour management is an important part of creating high quality data for print.
‘Only printers need to know about that’
At its most technical level Colour Management is way beyond the day-to-day understanding of those of us working around, but not actually in, pre-press and print. It can seem a minefield of acronyms and jargon best left to the specialists, but in fact everyone in the workflow of a printed product carries some responsibility for making it work, to ensure the best results. You don’t have to be a hard-core techy to do your bit. With respect, ignorance is no excuse.
There is no ‘should’
These days, where the high majority of images being used in design are digital files (rather than prints or transparencies as in days of yore) there can be an expectation that image files speak for themselves, that there is a definitive way they ‘should’ look in print, based on how images look when viewed on screen.
This is a myth which needs busting. If not managed correctly from the point the image is captured image files no more speak for themselves than any alpha or numeric character in a set. A given letter or number can be recognised as such, but with the use of any different typeface or font the same character can be displayed in any number of variations, some pretty similar, some very obviously different. The character is displayed in a manner relative to the typeface and font being used. Similarly, colour image files are relative to the colour profile being used to interpret the data contained within them. More on these later.
If you haven’t implemented at least the basics of colour management and you comment or complain to a repro company or printer that an image ‘should’ look like this or like that, they’ll be polite but will probably mutter something vile to themselves as soon as you’re out of earshot.
Why is knowing nothing about it a problem?
The mechanics of this cannot simply be left to somebody else downstream, assuming you mind how the images in your product are reproduced. Photographers, Designers, Editors and any others handling image files (even if just opening them to have a look before forwarding them on) are possibly, if they have no appropriate colour management protocols in place, unwittingly changing the colour profile supplied embedded in the image file to a default installed on their machine. This will cause the colour and other visual characteristics of the file to shift. Whether the brief is to accurately reproduce a photographer’s shot or a heavily artworked image I think we can all agree that really isn’t ok, and it’s very easily done.
Within a studio this could be happening more than once if files are worked on by different people and/or on different machines. This may be costing time and money in corrective re-touching and re-proofing to put things back the way they ‘should’ be, it could be causing tension in a relationship with a print supplier, or it could just be causing disappointing print. There are some pretty simple starting points for addressing this.
I am not about to suggest the purchase of an industry standard colour-accurate monitor such as you might see in a repro studio or a printer’s pre-press department, with the tools to regularly calibrate it, although having those is what you need to comment, with any certainty, on how things ‘should’ look.
If you want to do detailed re-touching and preparation of an image to be output in CMYK, to try and directly control the printed outcome, then of course you should have the right equipment (no, not iMacs, which really aren’t accurate when assessing colour for print) but that’s not the intention (or within the budget) of many freelance or agency designers, I think it’s fair to say. There are working practices more fundamental than that, which you would need to have in place whether or not you have the best hardware available.
Essentially everyone handling the files should have appropriate Colour Profiles and Settings set up on their machine. Using the now ubiquitous Adobe suite of design packages it is straightforward, and free, for anyone to get to this point.
What are Colour Profiles?
In our context, of preparing digital files for print, ICC Colour Profiles are software files containing data relating to particular types of RGB device (cameras, monitors etc) or types of CMYK printing (Litho sheetfed, Web offset, Digital etc) on different substrates (coated paper or uncoated paper, for example). Managing colour for different combinations of print processes and substrates therefore requires the use of Colour Profiles, both RGB and CMYK, which are appropriate to them.
Colour Profiles can be embedded in TIFFs*. Embedding the correct CMYK profile for your project therefore saves the image as it would look in the context of that type of printing. The same image file viewed in Photoshop, using a selection of different profiles, will look visibly different in turn because the data in the file has been interpreted differently by each of the profiles you’ve tried. Referring back to my previous analogy, you can re-interpret images with profiles in the same way you can re-interpret the same letters or numbers with different typefaces. Various print-related performance factors such as print process, dot gain and paper type are reflected in any given profile, so using the correct one matters. It’s not simply a question of choosing the one you like best.
This all relates (in Europe at least) to the ISO/FOGRA system, which comprises a set of approved colour profiles and agreed industry standards for achieving accuracy in digital proofing and printing.
At a point in the process RGB image files will need to be converted to CMYK. Using appropriate profiles enables us to manage the conversion of those images from RGB colour into CMYK by allowing us to realistically preview the CMYK outcome of a given RGB image.
RGB has a much larger colour gamut than CMYK, so some loss of colour is often the case as a result of the conversion, but using appropriate combinations of profiles will give you the smoothest transition and a much better idea of how it ‘should’ look in CMYK, when you’re viewing on screen.
When using the Gamut Warning in PhotoShop you’ll see what issues that image presents when converting between the two profiles. Even without all the hardware investment needed to convert to CMYK at the highest level of accuracy it’s hugely beneficial to your understanding to be able to preview, on an image by image basis, the kind of conversion issues which can arise.
*and other image file formats too, but for halftone images intended for print you should really be using TIFFs.
Your Adobe suite set-up
The choice of profiles should be agreed with your pre-press and print suppliers before you start your project, and everyone handling the files needs to be geared up to manage the files in the right way.
The best way to manage colour across the Adobe suite is to synchronise the profiles and settings across the packages to ensure consistent practice.
Download my free guide to doing that, by completing the form at the bottom.
In truth Colour Management is a much bigger topic than I can really cover here, but without building it into your systems from the very beginning and having it running in the background all the time you could be taking some chances and limiting what you can achieve.
Using the right profiles and settings are really just the basics, but without having them in place you can’t meaningfully judge your results on proofs and then in print. Whether you are producing work at the lower or higher end of colour sensitivity I would suggest you investigate and implement the profiles appropriate to what you’re doing. You can expect a smoother workflow, fewer colour-related issues or disappointments, arguments and unexpected costs.
You can contact me if you’d like me to consult on anything further, to manage or help with a project.
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