Published in New England Printing and Publishing 2001  © Ron Ellis

 

How color management can change the way you work

By Ron Ellis

 

Color management is now viable. Technological improvements have come so far so fast, that color management is not only viable, but it can change the way you work and help save you money.

 

The push to change

Printers of all shapes and sizes are driving the need for improved color management tools as the conversion in prepress continues toward computer-to-plate (CTP) workflows.

First, it became obvious to the early CTP adapters that color management was critical, so printers began investing in color management systems (CMS) in their plants. Prior to CTP, few customers saw the reason to move away from their analog proofing system and toward slow and complex proofing systems that could not match color reliably.

Second, inkjet proofers became faster and less expensive, suddenly making color management more relevant – because even though these proofers are dramatically less expensive than old proofing systems, they are useless without color management.

Third, the manufacturers of industry leading Raster Image Processor (RIP) equipment that drive these proofers added color management capabilities to their software so that the color management data can be easily used to control the proofs.

And finally, manufacturers of other peripherals to support the industry such as Apple for its hardware and software, Microsoft for its ubiquitous operating systems, and Adobe for its Photoshop and other image manipulation software applications, understood the need for dependable color management tools for the graphic arts industries. Thus, true useful color management tools began to filter down to all levels of users.

 

What are the benefits of color management?

Two of the greatest benefits of appropriate use of color management are that proofs are accurate — including some ability to soft-proof a job on a computer monitor, and the significant cost savings involved. 

As long as color profiles are accurate (more on this topic later) and depending on the type of job to be printed, some proofing can be done looking at the proof on a computer monitor, saving time and money.

Additionally, the costs of hard proofs can be reduced dramatically. A Matchprint can cost as much as $70 when labor and materials are factored. A proof from an inkjet printer can cost as little as $1.50.

By using an inkjet device that has a large color gamut and color management, spot colors can be produced more accurately than with traditional analog proofing systems and as well as most high-end digital proofing systems. Instead of using a generic standard such as Matchprint, the proofing simulation can be customized to represent the exact press or process used in your plant. In addition, using color management can help bring you closer to your customers by giving them tools so they can see how color will reproduce prior to sending the job to you.

One negative aspect of color management is that it can be confusing and difficult in the beginning. Having experienced help can get you there faster with less pain.

 

The importance of color profiles

Nearly all color management systems are based on the use of color profiles. The standards for these profiles were developed by the International Color Consortium (ICC). In the past, most color management systems used proprietary methods of describing and correcting color. If you were not an experienced scanner operator, you probably found it difficult to describe and correct color for your clients. ICC profiles take much of the guesswork out of managing color.

ICC profiles use the LAB color space (a device independent color space) that contains a wide gamut for mapping colors outside of the normal RGB and CMYK color models. By attaching an ICC profile to a document, an application can change how those colors are displayed or printed.

“In an ICC workflow, profiles can be used in two ways,” said Marc Levine, technical manager at Monaco Systems, a manufacturer of color management software.  “Profiles can be used to optimize the color transformation from one device to another. The most common example of this is getting your print to match your monitor.

“Secondly, profiles can be used to simulate the look of one device on another (typically called “proofing a device”). In the second case, the proofing device should replicate the limitations of the device being proofed, even though it may be capable of printing a wider range of colors,” Levine said. “For example, a dye-based inkjet proofer can be used to simulate the look of a standard web offset press (SWOP).”

The profile itself is only part of a CMS workflow. The RIP software being used must support ICC profiles. Not all software supports ICC profiles in the same manner.  For example, the RIP driving a proofer or platesetter must support ICC profiles in order to make use of these profiles. Different RIPs use different CMS engines to interpret the ICC profiles and apply needed transformations. So even though an ICC profile describes a device, different RIPs software will use that profile differently and with differing results.

The big idea is that not only do you need an ICC profile, but a RIP or software that implements the CMS transformations correctly. A good example is Adobe Photoshop. Photoshop not only uses ICC profiles and has a built-in CMS engine, but the results are spectacular and many users report good results using color management and Photoshop.

In contrast, Adobe PageMaker also can use ICC profiles and has integrated a CMS engine, but PageMaker has trouble showing images on screen and is not recommended for using ICC profiles to soft-proof results prior to printing.

To summarize, color management requires not only ICC profiles, but software or a RIP that takes advantage of these profiles. When working properly, you insert the profiles in your RIP software, and when you print, the RIP will use these profiles to give you the simulation you desire. To do this, two different profiles must be created.

 

Destination profiles and source profiles

The first profile is typically called a destination profile and is used to make the output device print as accurately as possible. The second is called a source profile and is used to simulate or show the limitations of the device being emulated.

ICC profiles can be created for a display monitor, for a scanner, and for output devices. In addition the output device may use another device’s profile in order to simulate that device itself. (For example a monitor or an Epson proofer can both use a Matchprint profile to simulate how the Matchprint will appear.)

These profiles can be used in many ways to help smooth production. The most common ways these profiles are used is to create simulation proofs, improve quality, softproofing, and to cut costs. For example, several profiles are used to create a simulation proof of a Matchprint on an Epson 10000 inkjet printer. The destination profile is of the Epson 10000 and is used to help the Epson itself produce color as accurately as possible and to get the widest possible color gamut out of that printer.

The second profile is the source profile and will represent the Matchprint proofing system that is being emulated. Both profiles will be applied in the RIP. For example, the destination profile is used to make the Epson print as accurately as possible, and the source or Matchprint profile is used to limit the colors down to the characteristics of the Matchprint.

It is important in this example that the Epson have a larger color gamut available to it than the color gamut of source profile, otherwise the Epson will not be able to accurately represent all of the colors to be translated from the reference (Matchprint) profile. In addition, in some RIPs, spot colors outside the color space used by the source profile can be mapped to the space used by the Epson allowing you to accurately represent hard-to-show spot colors.

In addition, if the RIP allows mapping of spot colors, and the color gamut of the printer is larger than that of the destination profile, you may be able to get really good results proofing spot colors. For this to be the case, you must have a proofing device with a large color gamut, as well as an RIP that allows you to map the non-CMYK colors in LAB rather than the already limited CMYK. (A good example of this is the Best ColorProof RIP and the Epson 10000, which together have a good reputation for being able to reproduce spot colors). Being able to accurately reproduce spots colors is not a given however.

 “An ICC profile does not expand the gamut of a printer, it quantifies it,” said Levine of Monaco Systems. “Using a quality profile for an output device can maximize your ability to reproduce color within a device’s gamut, which in the case of printers, is primarily determined by the ink and media combination used by the output device.

“A common misconception is that the addition of light printing ink substantially increases the gamut of a device,” Levine said. “In reality, light inks provide little or no increase to gamut size as they are only “watered down” versions of their darker counterparts. Light inks are used specifically to increase image smoothness and not to expand the device gamut.”

  The same source profile being used to make the Epson simulate the proof can also be used to make a monitor and copy of Photoshop 6 simulate the proof. Once the monitor is calibrated, the proof profile is picked in Photoshop and can show characteristics of the source profile.

 

What is a good candidate for profiling?

In many shops an analog proof such as a Matchprint or Waterproof is a good candidate for color profiling. That is because these proofs represent the only known and stable point in the printing process. These proofs are based on one stock, with fixed exposures and quality control, and if these analog proofs can be matched on press then they are a good starting point.

If the proof cannot be matched on press and is not accurate, or if the site is using a CTP workflow where there is no proof at all, then the press can be profiled.

In order for this to be successful, the pressroom needs to understand densitometry and should be able to run the numbers. In this case, the targets are printed on press on the common coated and uncoated stocks, and profiles are made. If there is good process control in place then these profiles will be accurate, and will show an even better representation of what you will see on press than profiling the analog proof.

“Color management has grown out of process control,” Levine said. “Process control keeps your devices stable. Color management communicates color between them. If you start with good process control, you will be successful. If not, you may find yourself wasting time and effort.”

The profiles are created by using color management software and a spectrophotometer. Typically creating a profile involves printing out a series of color patches and reading them back into the CMS. Patch sets can contain from 300 to 1,900 patches with about 1,000 patches being the most common. The more patches you read, the more accurate the results will be. The patches are read back into the software using a spectrophotometer.

The software then compares what the patches should be and the measured result can then be used to create a profile that accurately represents how the device being profiled represents color. The most popular color profiling software is made by Monaco and GretagMacbeth, although many other manufacturers such as Agfa, Creo (formerly Scitex), and Kodak also make their own versions of this software primarily for use with their products.

In general however, ICC profiles can be used interchangeably with systems from different manufacturers. (RIPs however use these ICC profiles in many different ways with different levels of success). The most popular graphic arts and prepress products are Monaco Proof and Profiler and GretagMacbeth’s Profile Maker.

All of these products allow you to interface with the most popular spectrophotometers and allow you to print patches, capture data, and create profiles using a number of settings regarding rendering intents, total ink coverage, black generation, and other settings that affect how the profile functions.

All of these products allow you to edit the profile as well. These products range in price from $1,500 (Monaco Proof) to $4,500 (Monaco Profiler and GretagMacbeth Profile Maker). Generally, the more you pay, the more control you have over the profile creation product. There are also some entry-level products such as Monaco EZColor for $300 that uses a scanner instead of a spectrophotometer to read patches. This product can give surprisingly good results, but does not offer the same level of professional control as the high end products.

The most common spectrophotometers are GretagMacbeth’s Spectroscan and the X-Rite DTP41. The Spectroscan is completely automated and costs approximately $5,900. The DTP-41 is a strip reader and requires you to hand feed strips and cost approximately $3,200. There are also several hand-held spectrophotometers such as GretagMacbeth’s Eye One and AvantesSpectrocam which cost approximately $1,500. For profiling inkjets, a UV filter is recommended for all of the above in order to compensate for brighteners commonly found in inkjet papers. For profiling monitors, all of the above except the DTP41 can be used, although there are a variety of inexpensive instruments such as the Spyder or the Monaco Sensor which are only recommended for monitors and sell in the range of $300. (Monaco also offers MonacoView to be used to calibrate single or multiple monitors). Many of the above products can be found in bundles. For example, Monaco is bundled with X-Rite and Best. Many of the bundles offer significant savings, and configurations that have been proven in production environments.

 

Implementing color profiles properly into your workflow

The most difficult part of color management is implementing the profiles properly into your workflow. The process can be confusing at first. It can help to have a consultant or trainer used to the process. The trick is to discover where in the workflow to apply the profiles to get the best results. It can be challenging because every RIP handles color management differently and some give you more control than others.

Even though there are many RIPs that can drive proofers, sometimes the aftermarket RIPs give you more control over color transformations than using the actual RIP that will be making the plates. For example, many traditional RIPs convert the data into CMYK and eliminate the ability of the profile to translate the spot colors in the wider colorspace of an inkjet proofer. In this instance, the colors are forced to CMYK and it is doubtful that hard-to-match spot colors will have any hope of being accurate. The trick is to figure out which combination of tools such as RIPs, color management software, instruments, techniques and workflows will give you the results you need. A couple days of a good color management consultant who has experience with many workflows and printing processes can save days of wasted time and take thousands of dollars off the learning curve.

Color management offers many potential benefits. Although there is a lot to think about, the tools have matured and exist to take advantage of all that color management has to offer. The time is right now for color management. The technology works and the return on investment can save a significant amount of money in proofing and quality control.

Ron Ellis is a prepress consultant specializing in workflow training and integration. He worked in the commercial printing industry for 18 years and brings a strong background to all aspects of prepress. He has consulted on numerous CTP installations and he provides color management, integration, training, workflow development, and troubleshooting solutions to the graphic arts community. He can be contacted at 603-498-4553 or through his web site at www.ronellisconsulting.com.