Color management is one of the most misunderstood areas of print, even amongst print professionals. Perhaps that is because it is not a concise system of predetermined actions, but is rather a continuum of knowledge and advisable behaviors intended to help practitioners to predict (and thereby control) the color of a final printed piece.
Color management theory is a response to what one might call the “Babel Effect”— that every color device (your monitor, your desktop printer, a professional color proofer, an offset printing machine) has its own unique way of representing color—its own color language. As a result, the same image looks different between one monitor and another, between digital camera or scanner and monitor, between monitor and inkjet proofer, between inkjet proofer and platesetter, and so on. Color management practice is the “Esperanto” of Color devices—a system whereby images can, in theory, be represented the same way on every device, every time.
While much more could be written on color management than is practical to state here, the following are a few need to know basics:
1. Color Space: The two primary color spaces are RGB (Red, Green, Blue) and CMYK (Cyan, Magenta, Yellow, Black). The RGB space, which allows a larger color range, is marvelous for reviewing and working with images on screen. The problem is, process color printing uses CMYK inks on paper, producing a much smaller range of color. It is therefore fundamentally important to evaluate your color based not on how it looks in RGB space on your monitor, but based on how it will likely look in CMYK space on your final substrate.
2. Color Standards and Color profiles: “What is correct color?” is the print industry complement to the conundrum of “How long is a piece of string?” International standards like SWOP (Specifications for Web Offset Publications) and GRACoL (General Requirements for Applications in Commercial offset Lithography) are sophisticated and objective baseline sets of color targets and tolerances around which cameras, monitors, proofing devices, plate setters and printing machines can be gauged and calibrated. While this does not resolve the subjective question of whether the color you see is “correct” or not, it goes a long way in determining whether the color you see on your screen or proof is accurate to the underlying color benchmarks. In layman’s terms, it lets you know “which way is up.”
For more on this subject, please visit the following link: www.swop.org/resources/Intro_to_SWOP.pdf
3. ICC Proofing: is a technique developed by the International Color Consortium, first initiated by Apple® in the 1990s. To make sure that each device you use through the process represents color the same way, one can identify the Color profile of one device and then load this profile on another device, allowing it to convert the image data in such a way that it will be represented on both devices in the same way.
4. Device Calibration: Device calibration is the process of adjusting the output of a color device to a target—a known standard like SWOP. It is limited by the range of color and the degree of refinement allowed by your devices. Hence, if you are a professional designer or photographer, you probably have expensive scanners, computer monitors and proofing devices as well as a spectrophotometer and color management software to calibrate your devices. If not, then to some extent or another, you are viewing your images through “Magenta-tinted glasses”. Only when you receive a digital proof from a machine calibrated to the elected standard will you know how your images really look.
5. Digital proofing and Soft Proofing: As the print industry more and more elects to eliminate the use of intermediary films in the print plate making process (CTP), digital proofs rather than traditional “Wet proofs” are used to check color before printing. The biggest advantage of digital proofing is that a calibrated proofing device adjusted to a color target, can provide very close accuracy of how your color will finally look on press. Soft proofing works the same way, without the paper. A properly calibrated monitor and a set color target allow you to see on screen a near approximation of the final piece. Digital proofing is not without its pitfalls though. See our head to head comparison of CTF vs CTP workflow to learn more.
6. Color Management in practice: In your work with China Printing Solutions, what this means in practice is that if you are a sophisticated color management practitioner and want to work with us from the start to control color, we can provide you with ICC color profiles and test proofs calibrated to SWOP, GRACoL or a device profile to gauge and manage color results from start to finish. If you wish, we may assist you in retouching photos or adjusting process colors to help you meet a desired result. If you are not set up to manage color in this way, the digital proofs we provide you will be pretty darn close to what you can expect in the final piece. If that red barn on page 42 turns out to be kind of orange, better that you know that at the pre-press stage than when a container of 30,000 pieces shows up at your door.
7. Shortcomings of Color Management:
The tragedy of Color Management Theory is that it is based on ideal circumstances that don’t really exist in the World.
A few of the limitations of the process are as follows:
—Images on monitors appear via transmitted light, images on paper appear via reflected light. Our brains perceive them slightly differently.
—Image devices have different ranges of color. While it’s possible to limit the color range that makes up an image on a device with a larger range, that’s a one way street. Meanwhile, colors out of range are going to be changed to the nearest approximation, which may in fact be dead wrong.
—Proofing paper is different than printing paper. There’s not a lot of range of proofing paper…if we proof on a thick and slick glossy substrate but print on an absorbent and slightly yellow substrate, it’s going to look different.
—It’s an imperfect process. Even with great attention to best practice, Calibration and Color management are challenging, and only work “so well. How close any device can be calibrated to a target depends on that device, the spectrophotometer, the software, and the practitioner.
—Images are considered stand alone, but print in groups. That red barn on page 42 that looked perfect on screen and on the proof is printing on a form right above a blue sky on another page. If we allow it to be the nice red we like, that sky is going to look more than a little purple. As a result, the art of compromise prevails…we pull back on the red a bit, resulting in a good looking sky and barn, if less than the ideal red.
Why bother at all, you may ask?
Printing remains a blend of art and science, and there is no such thing as a perfect print job. But the pursuit of perfection almost always produces far better results than no effort at all.