Pantone provides a number of tools designed specifically to provide colors that can be matched using CMYK inks. The they also provide their formula (spot ink) guide. Many colors within than can also be reproduced, many colors cannot. They actually show you within the guide which ones can and cannot be using SWOP CMYK inks.
All it takes is a calm and rational explanation to the customer as to why those colors are not an appropriate choice for CMYK reproduction. As I've stated previously, these people come to us because we are professional printers. They expect us to be able to do it, or at the very least be able to explain to their satisfaction why it's not possible. If you can show them the errors of their ways and explain to them the limitations of the process you will save them time, money and hassle down the road.
There's a tremendous amount of frustration that goes with color matching. I know this personally because for many years my business focused on fine art giclee printing. You think matching pantone is tough, try matching artists pigments with no formula guide. Color management solved 98% of these problems for me. It didn't allow me to match every color under the sun, but it did allow me to see if there was going to be a problem before I even started. It also provided the closest match to out of gamut colors without any fuss and muss.
The
sign industry is focused on CMYK and the fastest print speed possible. Other parts of the wide format market use printers with up to 16 colors and greatly increased gamut sizes. The Epson GS6000 is the first solvent printer to come standard with a special OG inkset (basically Pantone Hexachrome process inks). Since orange and green have traditionally been the weakest portions of the CMYK spectrum this inkset greatly increases the number of colors than can be reproduced. Pantone claims 90% of the formula guide, which they say is more than twice the amount that traditional SWOP CMYK can achieve.
Not all of that comes strictly from the OG inks. The Hexachrome CMYK inks are much brighter and more vivid. More like the inks we have on our inkjet printers. Even without the OG addition these inks would greatly expand the number of colors available on press. Much the way our inkjets are able to produce brighter more vivid prints than a traditional offset press.
For example comparing the gamut size of USWebCoatedSWOP, the default profile in the north american pre-press settings with the adobe creative suite to what I'm able to attain using a production speed on my inkjet (720x720 - 16pass on a cheap lustre finish photo stock). Shows that the WebCoated profile can only handle 50.3% of the colors that my printer is capable of. A much better comparison is to use the USSheetfedCoated profile which represents the sheetfed presses that we see more commonly. In that case we see that the USSheetfedCoated profile can handle 65.9% of the colors my inkjet is capable of. The inkjet is still able to produce almost 50% more colors than a sheetfed press using standard (non hexachrome process inks). The brighter hexachrome CMYK inks would definitely close this gap.
Now the standard color management with your RIP will automatically "boost" the colors you print. Mapping the smaller gamut to larger inkjet gamut. Especially if you're using a perceptual rendering intent. Here's the thing though. If you take the artists artwork and convert it to CMYK. You're cramming it all into those tiny little press gamuts. It remaps the colors to something that can be produced with it's smaller range of available colors. You see how this changes the colors. Especially if you're using the WebCoated default profile. Then your rip is using a series of mathematical algorithms to map the colors in that smaller gamut to the larger available gamut in either your canned or custom profile. So if you started with an in-gamut pantone spot, converted to CMYK and then sent it to your rip. You're going to have a hell of a time matching colors. First you took a color within your available gamut, changed it to fit within a much smaller gamut, and then "hope" that the gamut mapping of the perceptual intent will put it back to where it was to begin with. Now if you understand anything about how the perceptual intent works you realize that it's going to make hue adjustments anyhow to maximize the brightness and dynamic range of your photos. This creates a color shift on anything near the edge of the available gamut.
Using an RGB input work flow, and keeping the colors in spot form (maintaining their LAB values). Then making a single conversion in the RIP to a much more accurate custom profile allows you to print every color that's within the printers available gamut. Using the Relative Colorimetric intent will also maintain the hues better than perceptual will. Although this sacrifices some "punch" for greater accuracy. This method is far better at matching colors that are within the available gamut of your machine. Often many of the colors you're trying to match are possible. It's your workflow that's messing with them and moving them around. Far more than you realize are there for the taking. You're just hiding them on yourself.
The RGB workflow is a double edged sword however. Designers working in RGB will see all the wonderful colors available within the RGB gamut. Of which the production speed custom profile I noted above can only capture 45% of (adobeRGB1998). However, the end product produced by my workflow still provides up to twice the available colors as can be reproduced using a web offset press. It also produces a much more accurate representation of more pantone (or other reference guide) colors. If the designer thinks you're going to match every color on their screen then you will have a problem. In my experience they do not ever think this. If they have ever sent a job out before they've experienced the dramatic shift in color already. It might be difficult to explain to somebody's secretary why the RGB green prints so differently than what she sees on her screen, but most "designers" have either been schooled in the difference or experienced it already.
Having a ready explanation in layman's terms of the differences between additive and subtractive color helps to either explain the differences. Or it leaves them so baffled and impressed that they trust your expertise. I don't deal with too many of these issues as the majority of my clients understand much of this. Many of them have sought me out due to the expertise I offer in this area. Even the ones that don't get it, have it explained to them when they see a soft proof on screen. They see the differences in color and ask about it. I rarely provide hard copy proofs anymore. Another additional benefit of color management.
So there it is in all it's glory. The secret to my success. Although it's hardly a secret. This is just a summary of the proper workflow in a well maintained color managed shop. It's not as if it's my invention. I do attest that it works. It works very very well. If your workflow is set-up using CMYK. If you're using canned profiles. If you're using one profile for a variety of different medias and resolutions. If you cannot produce an accurate and neutral grayscale. You're doing it wrong. It might work for you. It might make you a lot of money. But when you want to moan and complain about how unrealistic designers are about matching colors. Then understand that there's plenty of shops like mine out there. The more you bullshit them with excuses and tell them it's simply not possible the more loyal they become when then finally walk into my shop or someone's like mine and see the difference. But don't let me tell you what to think, or what to tell your customers. You guys send a lot of business my way. Thank you for that!
BTW if you think you have it bad now, wait until you're having to compete with solvent machines that use not only a special orange and green, but blues, violets and reds. Pantone is hardly dead or antiquated. It's CMYK that is being shown the door. Digital presses and inkjet printers that allow for 6, 8, 10 or 12+ color set-ups that will knock your socks off in the years to come. We'll be buying a lot of ink in the future, but it will be filled with bright glorious color. Buy the tools and learn the methods you'll need to hit them all. You won't regret it.
