Building a Better Profile – It's All In The Recipe
by John Pannozzo
This 3D graph shows Srgb in the solid shaded area and the profile for Pictorico Pro High Gloss Film on an Epson 7900 shown in the wire frame. The Epson 7900 with HDR inks with an specific ink recipe can yield a color gamut far beyond the Srgb color space.
Building a better profile – It’s all in the recipe
Building, buying or downloading high quality profiles for papers can be a challenging hit or miss situation, often with more misses than hits. This becomes truer the further you get from common papers produced by the printer manufacturers themselves. Third party papers, fine art papers, specialty papers–even with a custom made profile using the best equipment can produce results way below what the paper is capable of.
So what makes it so difficult to produce a quality profile? Some people would have you believe that creating a profile is a mystical process that must be done every other day by a trained, highly paid professional. And should the stars not have been perfectly aligned when printing and measuring the target then the solution is simply to do it again. And again. (Or perhaps just tweak it.)
Color management to any device just shouldn’t be that difficult. After all color management came about to simplify the process of matching color to a device, didn’t it?
After the ink recipe is formulated for the paper a profile target with a large sampling of color will produce a very accurate and high quality profile.
In the wild west early days, manufacturers were responsible for the color produced on their devices. Color management promised and delivers consistency among devices. But it also put much of the responsibility for achieving that consistency on to the user, where it stands today. Which means, in large part, it’s up to you to make it work. And in devices like monitors and cameras it generally works well.
So why does it still seem so difficult for printers?
Well, the answer is–you don’t calibrate the printer. You calibrate the printer, the ink and the paper. And since the ink is usually a constant, and the printer is constant, then the variable becomes: ta da! The paper.
Or more specifically: how much ink a given paper can hold throughout the entire tonal range. We will call this the dynamic range of the paper. With hundreds of unique papers and coatings, that’s a big range of dynamic ranges. We can start to see the magnitude of the challenge. There’s never going to be one method of laying down ink that’s going to work optimally across them all.
This surplus of paper options isn’t a bad thing of course. In fact, I’ll step out on a limb here and say that the single biggest improvement in print quality over the last 5 years has come not from better printing hardware but from improved papers and coatings. But with this constant change and improvements, we have a large spread of dynamic ranges to contend with, and issues due to these differences are something a Printer Profile can’t fix. Yep, you heard me correctly–a paper profile can’t fix underlying problems associated with varying dynamic ranges of papers. It’s not its job.
So whose job is it?
It’s all in the recipe
Building a better profile isn’t just about, well, building a better profile. In fact, many of the most important decisions—like how much ink and in what combinations those inks should be used–happen way before the profile even comes into play. Truth be told, the profile is really only there to correct minor differences between a specified color and the color that ends up on paper. It has no control over the specific combination or amount of ink used to make the color. For that, the process relies on what we will call an Ink Recipe.
It’s important to note that by Ink Recipe, I’m not describing just the basic linearization tables that govern the total amount of ink for each ink channel (though it includes that information). An ink recipe is much more than that—or it should be. Depending on the driver or RIP used, an Ink Recipe may include ink mixing rules for a given paper coating as well as GCR/UCR and other driver specific controls that relate to how and how much ink is used. It characterizes every piece of the puzzle regarding where, how, and how much ink to put on the paper in a way that neither under-utilizes the paper’s capabilities, or overwhelms them.
Never heard of an Ink Recipe before? Well, it’s there, in some form or another, in every printing method. Trust me—it’s just disguised under a different name. For instance– if you print with the Epson driver you are probably familiar with its Media Type selection. At least you ought to be–it’s one of those things you better set correctly or your print won’t come out right. That’s because (in addition to some other things related to paper feeding controls), the Media Type selects which ink recipe gets loaded and used by the Epson driver.
No matter what you call it, some kind of Ink Recipe is always used when printing—even when the profile target (the one with all the swatches) is printed out with no color management in place prior to making a printer profile. What this means is: the printer profile is built to correct for a given printer–using given inks–on a given paper—with a given ink recipe.
That’s why it’s vital that the ink recipe you choose is always the same one that was used to print the target it was made from. If it doesn’t match, you’re probably not going to be happy with the outcome.
Because Ink Recipes are complex (at least good ones are) manufacturers usually create a limited set of them to cover a range of medias with similar coatings. The Epson driver Media Type setting has roughly a dozen selections, and all were created specifically for Epson branded media. Pick one, and the Epson Ink Recipe corresponding to that media will be used for everything sent to print.
So far so good. But... what if your media isn’t one of the available selections? Good question. Well, if it is still an Epson branded media you’re using, then Epson will tell you which selection to use as the closest match. If it’s a third-party media, then the person or company supplying the profile needs to tell you which Media Type they used when they created the profile. Be careful. If you pick the wrong one, then the profile will likely give subpar results. It might not be glaring—maybe a little over inking here, maybe a color shift there—but the profile will trying to correct for an inking situation it simply wasn’t made for, and somewhere, somehow, that’s bound to show a problem.
Even when you have all your settings right, you may still see issues if the Ink Recipe isn’t a good match for the paper. Manufacturers like Epson, understandably, build Ink Recipes just for their own papers (as you can see in their driver’s Epson paper-centric Media Type listing). But–there is a direct relationship between the Ink Recipe, the profile and the quality of the print. If one of them is wrong, or not well optimized for the characteristics of the paper, then the quality of the print will suffer.
If you are one of those who demands the very best quality your printer can provide and you don’t feel like you are getting it, even if you seem to be doing everything right in your profile settings, this may well be the reason why. The Ink Recipe may be limiting you before the profile even gets a chance.
For that, spectrophotometers and profiling software are not the answer. Save your money and your sanity. New profiles on top of bad recipes might move things around a bit, but the underlying cause is still there—a recipe that isn’t optimal for the paper. The real answer is a better Ink Recipe. Unfortunately, Ink Recipes are complex, driver specific, and not something you can create on your own.
If you suspect issues with the underlying Ink Recipes may be at the bottom of your color woes, the solution is a driver, a RIP or printing software that provides better, more accurate Ink Recipes optimized for the specific papers you plan to print on. (As well as providing a way to address new papers as they come out in the future.)
But what to choose? Besides the manufacturer’s solution there are a lot of printing options out there. Hopefully, this article has given you some new questions to ask when looking for the one that’s right for you.
One potential solution is ImagePrint. As one of the founders of ColorByte Software, ImagePrint’s developer, I have been involved for 20 years in the creation of ink recipes for printer and paper combinations. It’s a complex process–where profiles may take a couple of hours to make, Ink Recipes can take weeks if not months to perfect. This is why you see so few available in a standard driver and why you see none available for third party media.
I often get asked how the profiles for ImagePrint are so good. And although the answer is complicated, it is always the same. It’s what those profiles are built on that gives them the edge. Ink Recipes optimized for the papers we support – which is just about every paper worth printing on. In fact, using the right Ink Recipe is so vital you won’t ever see a selection for them in ImagePrint. That’s because we tag the recipe inside the profile so there can never be a mismatch and a bad print as a result.
To sum things up: When the Ink Recipe is correct, the profile has to do very little work to correct for the inconsistencies of the printer and media. If you ask the profile to do more than it was designed to do, the process will break down and the quality of the print will suffer. This will ultimately lead to much wasted ink and media, let alone frustration. I believe this is the single biggest reason why people don’t print as much as they would like to or stop printing all together.
The good news, there is a solution; sometimes you just need to look outside the box—and beyond the profile!
For more information about ImagePrint visit the ColorByte Software Website.
John Pannozzo has worked in the graphics industry since 1988. First as a system designer for broadcast video and animation. In 1992 ColorByte Software was born out of the need to print large scale computer generated graphic files to an Iris printer. The development of core technologies centered around color separation also paved the way for software development in the area of drum scanning. The last 10 years have been dedicated to the development of ImagePrint and the technology to enhance the printing capabilities of modern ink jet printers used in the production of photography and fine art print making.
*I recommend you read an overview of the Aardenburg display rating system. You can find that document here http://www.aardenburg-imaging.com/documents.html (It is the third file down.) At the bottom of the document is a little about the author and you can start to piece together not only his background and expertise in the field but also how his testing methods differ from that of Wilhelm and the significance of those differences.