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On the other hand, a custom profile is built in your shop to match your environmental conditions. The profile will also be created for the exact printer, ink and media you are using. When accurate color is critical, a custom profile is your best bet for achieving the results you and your clients are looking to achieve.

Typically, a canned profile is downloaded from the internet and installed into your RIP. The investment of time and money is minimal. So when a canned profile is good enough, the almost zero cost can be an overriding factor. A custom profile either needs to be built by you or a consultant you bring in to accomplish the task. In either case, there is a significant investment of time and money. In addition to the time, several square feet of media and ink will be required to create the color management targets that need to be printed and measured.

When Is a Canned Profile Okay?
Not all canned profiles are created equal. It's important to know the source of the canned profile, which in many cases can be difficult - if not impossible - to determine. You don't have a way of knowing if the profile was made by someone with extensive color management experience or a junior tech still learning the color management ropes. Usually there will be a big difference in the quality and reliability of a profile depending upon who creates it.

It's also helpful if the printer manufacturer has some input into the creation of the profile. Printer manufacturers know the best resolutions, pass counts, weaves and screening to use with each printer and media combination. If there is not a canned profile available for the quality mode you want to run, it's likely that it is not a recommended mode for the printer and media combination. But sometimes canned profiles do get built and distributed for print modes the device manufacturer would never recommend.

Premium media manufacturers usually retain or have on-staff color management professionals with the experience, knowledge and industry contacts to build the best possible canned profile given the limitations of environmental conditions. For example, our team was retained by a premium media manufacturer to build backlit profiles for their media in two specific models of printers made by one manufacturer. We worked with everyone involved to determine the best settings and actually built the profiles in the device manufacturer's US headquarters. We had access to experts and a very high-end spectrophotometer capable of creating backlit profiles. Without this instrument, it's unlikely you could make better custom profiles in your shop. So in this case, if this was a media and printer combination you were to use, the canned profiles would be good enough and perhaps even better than what you could have made yourself.

Which Spectrophotometer Is Right?
The previous paragraph referred to a high-end spectrophotometer, the Barbieri Spectro LFP, which is capable of creating backlit profiles. The LFP costs more than $10,000 and, while this is an extreme example of the investment necessary to make certain types of profiles, it is also an example of having the correct tool to do the job properly. The old story goes that while it's possible to cut a two-by-four in half with a hammer, it's far easier and more accurate with a saw.

The same holds true for spectrophotometers. There are instruments in the $1,200 range that will get the job done for most profiling projects. However, when one gets into specialized applications like ultraviolet cured inks and dye sublimation on fabric and glossy metal, instruments that are more capable and expensive will do the job accurately and easily. In some cases, this just means adding the IO table option for an X-Rite i1 Pro 2 if that's your instrument of choice. In other cases, it may mean you need a Barbieri SpectroPad for the larger aperture and different measurement geometry it offers.

Knowing which instrument you need is part of being a color management professional. If you don't have this knowledge, it's important to work your network to understand which instrument or instruments make the most sense for your profiling needs. This is also one of the advantages of bringing in a color management consultant to assist with your custom profiles. They will know which instrument is right and, in many cases, will own or have access to an instrument you might not otherwise be able to afford.

Why Create a Custom Profile?
Why would one want to create a custom profile if they are not experiencing noticeable color issues? The short answer is to save money. In our experience, a well-made custom profile will result in a 20% ink savings.

We have no good answer as to why most canned profiles put down too much ink, but we have developed some theories. The conventional logic for those who make profiles for inkjet printing is that more ink equates to more color. This is not the case. In fact, less ink usually equates to more color. Inkjet printing is a subtractive printing process, which means all the color you see is actually coming from the substrate or paper. A greater volume of ink blocks more light coming back to your eyes after it travels through the ink, reflects off the paper and returns to your eyes.

When you make a custom profile, you can adjust how much of each ink is laid down by controlling both the primary (or single channel) ink restrictions and the total area coverage settings. Neither of these is easy to change once a profile has been created, nor is it recommended you try to do so. Being able to set the primary ink restrictions that match your machine, ink, media and environmental conditions is probably the best single argument for building a custom profile.

Other Settings You Can Control
Right after you determine your total area coverage, it's time to print a characterization chart. Some refer to this as the ICC chart. It will have between 500 and 2,000 color patches, depending on the color management solution you're using.

Another advantage to building custom profiles is the ability to choose the number of patches in your characterization chart. There are situations where fewer patches are better and situations where more patches are better. As a general rule, you'll want to produce as many patches as can be easily measured in less than 30 minutes. This is where automated instrumentation can provide an advantage.

Once the characterization chart has been measured, you will be able to adjust several settings, such as GCR and black point start. These two settings are found in almost every RIP and, if the color management functionality is enabled in your RIP, it's often possible to adjust these for canned profiles as well.

Most RIPs allow you to set GCR via a drop-down list of options. The right place to start is medium GCR, although I've seen plenty of applications where maximum GCR has been applied and worked quite well. The only way to know for sure is to try different levels of GCR with some of your past jobs to make sure they still look acceptable.

Along with GCR, you can set the black start point. This refers to where a single black dot begins to replace balanced combinations of CMY. And one black dot uses a lot less ink than three dots of CMY. The result is less ink consumption. The higher you can push your GCR and the lower you can push your black start point, the less ink you will use.

Source Profiles and Rendering Intents
All the modern RIPs I work with provide the functionality to change your default source profiles as well as the rendering intents. In short, making these changes should increase your color gamut and the accuracy with which colors are reproduced. These changes are made independent of a canned or custom profile, so they will work with either, and could improve your color reproduction for existing profiles.

Input From Adobe I'd like to thank SGIA for their continued inclusion of articles on the importance of color management in the Journal. When reading the article, "Canned vs Custom Profiles," in the recent March/April issue, I did spot one issue which we wouldn't recommend here at Adobe, particularly when setting up RIPs based on the Adobe PDF Print Engine. While it is true that "changing your default RGB source profile from whatever it is (oftentimes sRGB) to Adobe 1998, because this will give you the largest possible RGB color gamut," it is often dangerous to do so if the creator of the content being printed had specified a profile other than AdobeRGB. Designers will often specify profiles in their creative applications and will have used on-screen previews in those applications to anticipate how a job will look when printed. Re-assigning the source profile from that which the creator specified will mean the colors will change on printing, and likely this won't match the expectation of the customer. The same is true if the user has specified a CMYK output intent when designing - simply substituting an alternate CMYK source profile will cause a color shift that the customer won't have anticipated. We at Adobe would recommend designers use a profile that is suitable for their monitor as the source profile. If they don't have a custom profile for their monitor, many monitors will have an sRGB mode (if they are conventional LCD panels) where they can then safely use an sRGB profile. If they are a wide-gamut display, they may support AdobeRGB, in which case it is perfectly safe to use an AdobeRGB profile as the source. In a case where a designer has not specified a source profile, in my experience, it is better when setting up a RIP for printing to anticipate the source conditions the designer would have experienced when creating the artwork. Particularly in cases when "user submitted" artwork is being included in a job that doesn't include a profile, maybe in situations when the customer has uploaded a photo or a design to a website to be printed on an item of clothing, or on some custom-printed item, it's much more likely the customer was using a screen closer in behavior to sRGB than AdobeRGB, and so we should be using sRGB as the default profile. "More gamut" does not always equate to "happier customers." Mike Scrutton Director - Print Technology & Strategy, Adobe

We suggest changing your default RGB source profile from whatever it is (oftentimes sRGB) to Adobe 1998 because this will give you the largest possible RGB color gamut. We also suggest changing your default CMYK source profile from whatever it is (oftentimes SWOP) to GRACoL 2006. The combination of these two changes should significantly increase the gamut of colors you can reproduce. The defaults that are selected by many RIP manufacturers are intended to line up with those of Adobe Creative Suite apps. The problem is that those settings in apps have not changed for a very long time. In fact, the SWOP profile used by default is about 20 years old.

In the same area you find the source profiles, you should also find rendering intents. Rendering intents tell the RIP how to map colors that are out of gamut between the artwork file provided and your output device. I suggest changing the rendering intent on your RIP to "relative colorimetric" and reviewing the printed results. In my experience, you will find that your color becomes more predictable and repeatable while your neutral grays become more neutral.

Wrapping It All Up
If you know the source of your canned profile and are comfortable with it, and if you tweak the settings we've discussed in this article, you should achieve acceptable and pleasing color for most of your work.

What you will not find with canned profiles is the cost savings that come with setting your own primary ink restrictions and total area coverage. In order to realize these gains, as well as achieve the best possible color, custom profiles should be built using a spectrophotometer appropriate for your ink and media combination.

Jim Raffel is a color management consultant who also serves as CEO of ColorCasters, LLC and ColorMetrix Technologies, LLC. As a veteran of the printing industry and a graduate of Rochester Institute of Technology's acclaimed printing management program, in 1995 he formed ColorMetrix to make an idea he had to make color measurement and evaluation easier by creating easy-to-use software solutions. Today as a certified G7 expert and color management professional, his consulting practice focuses on dye sublimation and flat-bed UV inkjet printing. He has also been authorized by SGIA to conduct color management boot camps.

This article appeared in the SGIA Journal, March / April 2018 Issue and is reprinted with permission. Copyright 2018 Specialty Graphic Imaging Association (www.sgia.org). All Rights Reserved.