Accurate digital sublimation is obtainable, provided those attempting it know what variables to manage and are willing to commit the time and practice necessary to become proficient. (Images courtesy Condé Systems Inc.)

The holy grail. The impossible dream. Simply not going to happen. Phrases like these are often thrown about in discussion of managing colors in digital sublimation. And to be fair, their use has been well earned by an industry that promoted sublimation to every imager, regardless of size, need or use. The truth is that accurate digital sublimation is obtainable, provided those attempting it know what variables to manage and are willing to commit the time and practice necessary to become proficient.

 

The first aspect to be clear about is what actually impacts color and consistency. In no particular order, the factors to be managed include: printer, ink, paper, press, substrate, RIP (raster image processing) software, profile, print file, conditions and time. A large list to manage, for sure… but it’s not impossible. 

 

Equipping for color

Significant improvements have been made in the last two or three years when it comes to printers. The most noteworthy change is that printers are now being made for sublimation as opposed to retrofitted from a vinyl or UV base. When in the market for a new printer, consider functions such as auto cleaning, bulk ink systems, take-up reels, service contracts and ease of maintenance. As for print speed, get accurate projections for the dpi levels at which you will (or expect to) produce. Once a printer is purchased, the focus turns to managing the ink flowing through it. 

 

The best practice here—routine cleanings and maintenance of the ink-delivery system before problems arise. Print heads and dampers are especially critical to allowing a consistent and repeatable flow of ink through the printer. A very small blockage anywhere in the ink-delivery system will create significant shifts in color spectrum and destroy repeatability.

 

There is such vast variety in the substrates used in sublimation, and the best results come from consistency. (Images courtesy Condé Systems Inc.)

Without debate, ink has been given more attention than any of the other components within sublimation systems, and with good historical reason. Ink was very expensive, inconsistent, clogged up the printers and, in general, underperformed compared to expectations. Fortunately, today’s inks are significantly better than those produced just two years ago. In general, the ink available today is more consistent, has a wider spectrum and flows through printers with much more ease than its ancestors. In fact, improvements may have been great enough to remove ink from the top of the “most critical variables” list. 

 

Continuing the trend of massive momentum over the last few years, we shift attention to paper. Four years ago I tested five different papers, each one producing dramatically different results. What was orange on one was dark yellow on another and cream colored on yet a third. Each paper’s release points were different, drying times varied greatly and the ability to maintain desired color was short. In retrospect, they were all pretty bad. Today’s papers are truly superior and much more consistent across brands. As with ink, the

choice of paper is now less about quality and more about repeatability, cost, stocking rates and service. 

 

Comparatively, I believe there has been less advancement in pressing technology than with any other component. Presses seem to have a greater difference across brands than what’s seen within other color-management variables. In some ways it’s understandable; pressing is simply heat, pressure and time. That’s it. Nothing fancy or overly complex—just a certain temperature, at a certain pressure, for a specified time, which would lead one to think it’s easy. But accomplishing this in our light industrial settings at costs that are manageable is a challenge. 

 

When purchasing a press, request that manufacturers run samples, and not just one or two. Ask them to do 20... of the same graphic. Test the full size of the press with one solid dark-colored block to ensure an even color transfer throughout. Find out how many thermostats are on the press and get independent heat readings across the heating platen at the same time. Some presses produce shocking temperature inconsistencies. 

 

With a heat press settled on and in shop, be sure to use this equipment in the same manner each and every time. Most presses are manually cycled, so make it very clear to the operator that the machine must hit the exact time, every time. Even a two-second difference in pressing is enough to alter the outcome. Take this step seriously and manage it critically for much better results in the long run.

 

Of products and profiles

There is such vast variety in the substrates used in sublimation, and the best results come from consistency. Whatever the product, make certain that it’s coming from reputable and stable suppliers and preferably, those that control the production of the items. 

 

When purchasing a press, request that the manufacturer run several samples of the same graphic (Image courtesy the author)

A few good RIP software programs are available on the market, some provided by the printer manufacturer and others offered as aftermarket options. Each has its strong suit; many sublimation professionals simply have workflow preferences that lead them down one path or another. The important point to understand is that each will interpret artwork differently; a switch between RIPs won’t achieve the same result. Going back to the consistency issue, pick a setup that works and stick with it. Constantly changing the pieces and parts will never lead to dependable color production.

 

In terms of color vocabulary, a profile is nothing more than a program that instructs the RIP how to interpret the colors in the artwork. Each profile change will alter the amount of each color of ink that comes out of the printer. Different profiles will have dramatically different outputs, even when everything else in the system remains constant. In fact, the profile used will arguably have the single greatest impact on color gamut, range, ink usage and net results. 

 

Another influencing factor is the actual file that’s printed, which can change the color output. To see this in action, take the same file and save it as multiple file types. In the last few years, these variations have decreased and some file types will produce very similar results, but discrepancies still exist. Because of this, it’s important to create the same file types where consistency and repeatability are desired.

 

Beyond purchase parameters 

Believe it or not, the print and production environment will also have an impact. Up until recently, an imager could print the same file at high or low humidity, varying temperatures and, some would argue, even different barometric pressures and get slightly different results. These factors have been minimized with improvements in paper and ink, but humidity will still play a roll in quality. Watch humidity in the print room as it often reveals visible differences in drying time between low and high humidity situations. For instance, it is not uncommon for a file that prints very well at 50 percent humidity to have difficulty drying when printed in a climate with 80 percent humidity. A climate-controlled print room including humidity may never realize these effects, but those who live in areas with varied humidity will attest to the change.

 

A final factor in consistency is time. The longer printed paper sits without being transferred, the more the colors adjust. What was once noticeable in only a few days or weeks is now typically months, but environmental elements play a huge role here too. Don’t be surprised when color shifting has occurred if a few weeks have passed while the image has been exposed to significant swings in temperature and humidity. 

 

Equipped with the knowledge of the 10 factors that shape color management, the key is to install processes in your facility to control and manage them. A few years ago, upgrades in color were mostly based on improvements to the inputs. We are now entering a time where most momentum will come from knowledge and management within the printing shop, with a developed understanding in profiling, linearization, heat, time and so forth. Our comprehension of these chemical and physical processes will help progress the industry beyond its current level. The most successful companies able to hit and manage color are those that appreciate all the variables, how they interact and how to solve problems creatively as they occur. Inputs have gotten us this far; it’s now up to our desire, entrepreneurship and ingenuity to move forward within digital sublimation.