Deane Nettles | Advertising & Graphic Design

COLOR MANAGEMENT

Color management is the search for a system that will allow you to be able to have the color you designed on your computer screen match the PDF proof you sent to your client, the hard proof you get from your printer and the final printed piece that comes off the press both here and in Singapore.

Currently, and possibly forever, the most expensive color management system available will only bring the color on all those systems into an approximation of each other — your eyes are more accurate than almost any reproduction device. But color accuracy is getting better all the time.

OBSTACLES TO COLOR MATCHING

  1. RGB is not CMYK. You design on a monitor which represents color as RGB, an additive color model in which red, green, and blue dots of light are added together to reproduce a broad array of colors. It has a fairly wide color gamut (a wide range of colors), but doesn't reproduce cyan, yellow, white or black well. And you are designing a piece on that RGB monitor that will be printed using CMYK, a subtractive color model which reproduces color by absorbing different wavelengths from white light reflecting off a piece of paper. CMYK has a relatively smaller color gamut, poor reproduction of many oranges and greens, but higher contrast than RGB. Because of this, color on your monitor will never truly match the color on your printed piece.
  2. Monitor calibration. Go into a department store and look at a bank of TVs. Even though each TV is receiving exactly the same signal, the color on the TVs looks different, sometimes dramatically so. Your computer monitor is the same way — each one has it's own special color characteristics. So the PDF you are looking at on your monitor doesn't look like the PDF on your client's monitor which doesn't look like your printer's calibrated monitor. To prevent color fights with your client, calibrate your monitor and insist that they calibrate theirs — at least then you have a chance of working it out. And calibrate your monitor to 6500k, not 5000k. It's confusing, but daylight white on a monitor is 6500k, and overhead and task lighting is 5000k (D50), as mentioned below.
  3. Just like monitors, ALL recording devices record color differently. Each camera records color differently, which is why some photographers prefer Nikon, and some prefer Canon. And different scanners record color differently. Finally, each inkjet printer, and each kind of paper you run through that printer, prints color differently.
  4. Light is different colors. The fluorescent in your conference room are a different color than the tungsten lights in your client's work space which is different from the color-balanced lighting in the color room at your printer's. (Even color-balanced lights from different manufacturers can have slightly different properties.) And then there's the issue of colored walls, which can affect color both by bouncing color onto your artwork, creating an overall color caste, and by affecting your visual perception of color. Have an area in your office where the light is color-balanced and the walls are a neutral grey where you can reliably proof color, and invite your client there to inspect color.

    5. In addition, there are different color balance standards, depending on what country you are in and what material you are printing on, such as:

    • D50 Noon Sky Daylight at 5000K is used for the evaluation of color quality and uniformity in conformance with ANSI and ISO specifications for U.S. printing.
    • D65 Average North Sky Daylight at 6500K is used to provide visual correlation with spectrophotometric readings or in conformance with Automotive, Textile, and European or Japanese printing standards.
    • D75 North Sky Daylight at 7500K is used for visual evaluation of opaque material as outlined by ASTM D 1729.
  5. Everybody has different levels of training, expectations, and patience. As a graphic designer, your eye is trained to see color. The eye of a cosmetics manufacturer is even more highly trained. The CEO of a technology company, who may be able to see that you've put the wrong model of their widget in the photo when they all look the same to you, may only be able to distinguish between olive green and grass green when they are placed next to each other. And the pressman may not be willing to see the difference between an orangy-red and an orangy-orangy-red if he's under pressure to get on to the next job.
  6. Each printing press is different. And your printer may have an ICC profile for that press, but it's not easily available to the designer, or the designer doesn't ask. Or the designer doesn't know the difference between — or doesn't know the job is running on — a digital, sheet fed or web press and so doesn't change settings to compensate. In addition, there are differences in how inks print (traditional ink vs. soy-based vs. UV, alcohol vs. waterless, high quality vs. low quality), how paper affects color (glossy vs. matte vs. uncoated, and the color of the paper itself) and how changes in line screen (both resolution and type of line screen, such as stochastic) can affect color. Use a reputable printer, talk with them, and work with them more than once and you will get better color.
  7. Finally, there are your computer programs' attempts at color management. Prior to Adobe CS2, the CMYK numbers for Pantone color chips in Illustrator were different than the numbers used in Photoshop, and then the numbers changed again in Quark or InDesign. And those numbers often changed from software version to software version. Fortunately, since Creative Suite 2, all Adobe programs get their numbers from Adobe Bridge, reducing the insanity. You can also synch all Adobe programs to the same color space using Bridge (Edit>Creative Suite Color Settings), which will further help with color consistency across programs.

10 STEPS TO "PERFECT" COLOR

Here are the steps required to have the color you see on your screen look that way on press. Equipment required can be had for less than $1000. The cost of the color proofs from your printer should be included in any printing estimate and are passed on to the client.

  1. Calibrate your monitor (calibrator costs roughly $215).
  2. Get a CMYK icc profile from your printer and set all your programs to the same .icc profiles using Adobe Bridge in Edit>Creative Suite Color Settings using that CMYK .icc profile,
  3. Have your photographer (or illustrator) send you their files with their .icc profiles embedded in the file and with approved hard proofs.
  4. Get a RIP for your inkjet printer (or buy a more expensive inkjet printer with a RIP, or buy a color laser printer with Postscript capability), and then get a custom .icc profile for your inkjet or laser printer (about $99 from places like Chromix) and learn how to use it.
  5. Get a color viewing booth and check your proofs in it (like these; price depends on size and if the booth is for proofs only or transparencies and proofs).
  6. When you are satisfied with your hard proofs, have your client come over and approve them in your viewing booth.
  7. When the client has approved the proofs, collect for output and send your
    • live files or press-ready PDFs,
    • a full set of hard proofs,
    • any Pantone chips for matching spot colors you are using,
    • and any hard proofs from your photographer or illustrator
    to your printer.
  8. have a high-quality hard proof pulled by your printer, go to the printer's office, compare their proofs to your proofs and color chips, and have them adjust the job files until your printer can output a set of hard proofs that match the proofs your client approved (or explain why they can't).
  9. have your client meet you at the printer's and approve those hard proofs or make further corrections (repeat until client signs the proof, verifying that they are satisfied).
  10. And finally, go to the printer's plant when the job is being printed for a "press check" — to inspect the printed work as it come off the press. Check the press sheets against the approved hard proofs, and have them adjust the press settings until the press sheets are close enough to the proof that you are satisfied. Sign the approved press sheet. The printer is then responsible for printing the rest of the job to match that sheet.

LEGALITIES AND GOOD-ENOUGH COLOR

The preceding 10 steps are the most accurate way to work. They also legally protect you as long as the final printed piece reasonably matches the approved proof. (And this process also allows everyone several steps to catch the mechanical and typographic mistakes that should have caught before sending it to the printer.)

However, clients will press you to keep costs down and jobs tend to move more and more quickly through the studio. Great color takes time and therefore costs money. Please fight against the tendency to adopt "good enough" color management — itemize proofing and press-proofing in your job estimates and explain that it is required to guarantee a quality job.

At the same time, realize that for many clients, "good enough" color may just BE good enough. (All the client sees is an RGB "soft" PDF proof on their uncalibrated monitor, you only see inexpensive inkjet proofs from your uncalibrated printer, there's no press inspection.) Us old guys may not like it, but like much in life (CDs vs. vinyl, iPad vs. real books), price and ease win out over quality.

If you are doing "good-enough" color, at the very least get a good quality monitor calibrator and use it. Your eye will be responsible for the color, and if your monitor isn't calibrated, you're flying blind.

Traditionally, designers purchased the printing job from the printer and then added a percentage of profit before reselling the job to their client. But if your client only wants to pay for soft proofing AND has high color standards, you may prefer to have the client purchase the printing directly, so if there is a problem with the color you aren't left with a dissatisfied client, a bill from the printer, and no easy way to resolve the dispute.

SOFTWARE COLOR MANAGEMENT

Color management on the computer is dependent on .icc profiles. .icc profiles are little bits of computer code that say what colors the device that created it are capable of reproducing, compared to a recognized standard: generally LAB color, a mathematical construct that includes ALL of the colors the human eye can see. Files that do not have an .icc profile embedded in them are nobody's friend. If your printer receives a file without an embedded .icc profile, they don't have any idea what it's supposed to look like — it could be reddish, bluish, neutral — and will print it the way they think looks good. Cameras and scanners usually embed their profiles in the files automatically. But if you are creating original art in Photoshop or Illustrator, it's up to you to make sure your file has an embedded .icc profile. THose programs ask you if you want to embed the profile when you save the file.

PRINT SETUP. In Adobe Creative Suite, it's SIMPLEST to go to Adobe Bridge, go to Edit>Creative Suite Color Settings and synch all your Adobe applications to North American Prepress 2. This sets your RGB color to Adobe RGB (1998) and your CMYK color to SWOP (Standard Web Offset). SWOP is a standard press setting that your printer will have experience converting from.

However, it is best to check with your printer on how they want you to set up your files. Many printers have custom profiles for their presses, which they would prefer you use.

(Adobe Suite and Quark allow both CMYK and RGB images to be used in their files. There is a movement to send RGB files to be sent to the printer and have the printer responsible for CMYK conversions to match their press. This field is a moving target right now, so it pays to ask your printer if they support this.)

PRINT & INTERNET WEB SETUP. In Adobe Creative Suite, it's SIMPLEST to go to Adobe Bridge, go to Edit>Creative Suite Color Settings and synch all your Adobe applications to North American General Purpose 2. This sets your RGB color to sRGB (1998) and your CMYK color to SWOP (Standard Web Offset). sRGB is the standard RGB for Internet Web design; it does not have as wide a gamut as Adobe RGB for print reproduction, but if you use Adobe RGB and don't convert before using it for the Internet, your Internet images will appear slightly reddish.

[Problem: SWOP vs. Sheetfed, standard vs. ideal. Graphic designers, other than publication designers, rarely produce work for web presses. Web presses are for magazines and other really large runs. Most of the design work I do is for short-run sheetfed presses. So my setup preference is to go into Illustrator or Photoshop, go to Edit>Color Settings, select North American Prepress 2, and change the CMYK settings from SWOP to "U.S. Sheetfed Coated v2," and save those custom settings as "North American Prepress Sheetfed." That custom setting will then be available in Bridge. I do this because the gamut for a web press is smaller than that for a sheetfed press, and so I can get better quality if I use the sheetfed setting. To get the absolute best quality, get the profile for the press you're really running on from the printer you are using, and use that for adjusting your images in Photoshop, and for outputting pdfs.

Rick Hacker at printer HBP agrees with using U.S. Sheetfed v2 over SWOP for sheetfed presses, but they prefer to supply their own press profiles to clients.

Joe Wagner at Whitmore Printing says that they "prefer CMYK workflow for commercial print using our press profiles — just call and ask. If RGB files come in they need to be converted; and then there is an issue of charging for color management. And exactly what is the designer looking for on critical color issues – cosmetics, food, fashion, automobiles etc…..This should all be discussed up front. Digital, wide format and Giclee can be CMYK or RGB. And Adobe CS3's and CS4's mixed RGB and CMYK print workflow does work."]

CONVERT TO PROFILE RENDERING INTENTS

When converting from one .icc profile to another, you can get choices in what is called "rendering intent." Here are some definitions.

Perceptual — Maintains white point. Desaturates colors overall so first gamut fits in 2nd gamut. Preserves color relationships.
Saturation — Converts colors to the nearest equally-saturated color, so color relationships change. Good for charts and graphs.
Relative Colorimetric — Best place to start. Maintains white point while adjusting colors to the nearest available color by the numbers. Particularly useful if you are converting to a larger gamut (with black point compensation turned on.)
Absolute colorimetric — Doesn't maintain white point relative to rest of image — can result in apparent color cast. Mostly good for proofing and flat color Illustrator conversions such as logos.

Better yet, please read Bruce Frasier's article at creativecolorpro.com, which the above is based on.

Bruce's recommendation: try Perceptual and Relative Colorimetric, and see which one looks the best. (Sometimes neither one will.)

PHOTOSHOP WORKFLOW

  1. Always embed an .icc profile in your files when you save. As I said, an untagged file is nobody's friend, as there is no reference for what that file should look like. To add or change profiles in Photoshop: Go to Edit>Assign Profile or Edit>Convert to Profile. (If you have an untagged file, you want to Add Profile, because it won't alter the data, just change how it's color shows on the screen. If you have a tagged file, you want to Convert. Either one previews on your screen before you make the change. See Assign vs. Convert Tutorial.)
  2. Black Point Compensation button. When you need to change an image from one profile to another, turn on Black Point Compensation unless you are converting from an RGB profile to an RGB profile.
  3. Work in wide-gamut, high-bit depth RGB. Ideally you want to scan at a high bit depth (12-bit or higher) or shoot at a similar high bit depth in your camera in Camera RAW format. Convert your camera images to Photoshop format via Adobe Bride (Edit>Open in Camera RAW). Then open either type of image in Photoshop and convert to the new profile PhotoPro RGB (which has an extremely wide color gamut) before you begin editing. The high bit depth and wide gamut will give you the most latitude to make corrections with the least chance of creating banding (gradations with obvious steps in them) when you adjust your curves; it should also linearize your color so you can make brightness changes without color shifts. (The Bit Depth Decision by Andrew Rodney, Digital Photo Pro magazine.) Just beware that your images will be many times larger than you are used to, because of the increased bit depth.

    4. There is no need to convert 8-bit images to 16-bit images, as you won't gain anything. You don't need to convert Adobe RGB (1998) images to PhotoPro RGB, because you won't gain anything. You do want to convert sRGB to Adobe RGB(1998) if you are going to make changes to the file.

    Note: The advantage of 12+-bit and PhotoPro RGB is that they are really hi-performance settings. The disadvantage is that it's likely that the other people in your office won't understand what they are dealing with — particularly about bit-depth. I recommend that you explain to your production manager or one fellow designer what you're doing and why, so when you're out sick other people won't get confused by your workflow. Or convince everyone to work this way.

  4. Adjust color in Camera RAW, then adjust color in Photoshop. While you're at it, experiment and learn about Adobe's Camera RAW application — may types of color correction can be done quickly in Camera RAW that can't easily be done in Photoshop, particularly overall color correction. And some color corrections can be made in Photoshop that can't be made in Camera RAW.
  5. CMYK Very Last. When you are all done with all corrections to the photos or artwork you are working on, save it as your Master RGB file. Then save a copy of the file and convert it to the CMYK profile appropriate for the press it will be run on, and import that file into Illustrator or InDesign.

Remember: Keep your Master RGB file and convert from it to other .icc profiles for each usage because each profile has a different color space, and constantly converting an image from one profile to another will degrade your color information, just like continually saving a jpeg will make it look worse.

Raster Image Processors (RIPs)

It used to be you needed a RIP to render vector (Illustrator) art on an inkjet printer without getting "jaggies" on any line that wasn't a straight horizontal or vertical. Now that inkjet printers have such high resolutions (1440dpi+), this isn't such a problem. And the inkjet printer's overall color accuracy has greatly improved as well. But if you want to color managing your printer, the only way you can do it is with a RIP.

I asked Chromix (http://www.chromix.com) what they recommended, and here's what I got back:

"Wow, that's a big question. There are a lot of RIPs out there.

"We have made a point of not getting into the RIP-selling business. RIPs are often hard to understand and use, and a lot of times we suggest that people stay away from using a RIP unless they have a reason why they need to use one. We do sell and recommend the ColorBurst RIP [which works with Epson printers]. We know and respect the people who make it. It has all the right ingredients that a quality RIP needs to have: Linearization, per-channel ink limiting, total ink limiting, the ability to turn on and off color profiles. ColorBurst also has an unusual quality for a RIP in that it is fairly straightforward and easy to understand.

"We would only recommend the full-featured ColorBurst RIP, not the free version that comes bundled with some Epson Printers."

ColorBurst RIPs are pro-level and a bit pricey. But they are located in Ashburn, Va., so you can support the local economy.

http://www.colorburstrip.com/

INKJET RIP OPTIONS

There are four ways of setting up an inkjet printer to work with color management. Take and print your artwork directly through Photoshop to the printer with color management off for your baseline. Then try your RIP these four ways from your page layout program to see which prints closest to the original.

  1. Adobe CM OFF / Epson CM OFF / RIP CM ON
  2. Adobe CM ON / Epson CM OFF / RIP CM OFF
  3. Adobe CM OFF / Epson CM ON / RIP CM OFF
  4. Adobe CM OFF / Epson CM OFF / RIP CM OFF

You NEVER want more than one CM set to ON because the color management will be applied more than once and you'll have a mess.

COLOR MANAGEMENT REFERENCE

Here is a slightly different explanation of color management using toast.

READ THIS FIRST
Color Management Primer, an overview. (Mentioned below as well.)

READ THIS SECOND
Color Workflows for Adobe CS3. (Relatively) simple instructions on how to set up CS3 for the workflow you need. There's some wishful thinking about how close we are to RGB workflows, however. Downloads as a pdf.

READ THIS THIRD
Working Spaces in Adobe Applications. Color gamuts, maintaining color gamuts, and picking the right color gamut in Camera RAW.

READ THIS FORTH
Working with images in a color management workflow. Steps for editing color in Photoshop.

READ THIS FIFTH
Color Management Myths. If you're like me and had heard little bits about color management over the years, well, some of it is wrong.

For more information on color management, check out:

BOOKS
Real World Color Management (2nd Edition)
(Real World) by Bruce Fraser, Chris Murphy and Fred Bunting. (Amazon reviews say it's the best book available.) Very geek but very highly rated.

Real World Adobe Photoshop CS3 (Real World) by David Blatner, Conrad Chavez and Bruce Fraser. If you thought you knew Photoshop, this book will kick your butt. Explains what all the different controls do in both Camera RAW and Photoshop, tells you which ones not to use, shows you a lot about non-destructive color correction and even some about correcting "by the numbers."

SITES
Most current GRACol (General Requirements for Applications in Commercial Offset Lithography) and SWOP profiles:http://www.gracol.org/resources/iccdownload.asp

Two color management sites recommended by Chromix:

"Andrew Rodney has an extensive library of pdfs covering many aspects of color management and Photoshop tips and tutorials. For example, there is a 4-page "Color Management Primer" that explains the history of, and why we have and need, color management. His opinions are informed and objective."

"The Colorsync User's List has evolved over the years to go beyond Apple's Colorsync application, and has become a highly respected forum where the top color geeks around the world discuss color management, and thousand of others subscribe to the list just to read what they have to say."

COMPANIES
Dodge Color, Silver Spring, MD, high-end color house specializing in work for the US Postal Service and offering a variety of photographic and digital services.

Chromix, Seattle, WA, provides custom icc profiles, great prices on calibrating equipment. Get their newsletter or check back issues for color management issues. Great for in-house profiling, not as strong with printing to press issues.

X-Rite, provides top-of-the-line Gretag-Macbeth and other calibrating equipment.

Apple: Their notes on Quartz color management

WEBSITES
Color Wiki