The Critical Role of Inks
By Kim Crowley
Dye-sublimation (dye-sub) allows print service providers (PSPs) to expand their offerings into more diverse substrates. It requires special attention to the process and tools in order to achieve consistent quality and color. Ink, along with special color management considerations, are factors that cannot be ignored.
RJ Sullivan, product manager, EFI, says managing color with dye-sub on textiles is an art. “Not everyone can do it. You need equipment that reads color off of textiles, because it’s not the same as reading it off of vinyl or paper.” He adds, “If you learn how to profile and understand the interactions with the ink, substrate, and heat press, you develop a competitive advantage.”
What Buyers WantPrint buyers request high-quality prints true to original designs. Color is especially important for matching corporate branding elements. “Typically print buyers are concerned with brilliance and pop more than actual color matching. It becomes important with skin tones or specific colors for logos,” says Daniel Slep PhD., director of technology, Hilord Chemical Corporation.
“The biggest problem we face is educating the customer that there is no direct correlation between process color and CMYK, but this is an issue related to digital printing and not specific to dye-sub,” explains Michael Labella, product manager, US Sublimation. Otherwise, he continues, matching colors with dye-sub is actually easier because of its wider color gamut.
Paul DeWyngaert, VP development and application, SpectraJet, notes that print buyers are realistic, but they expect what they are told they are going to get. “PSPs are sometimes too eager to promise something they know will be difficult because they don’t want to lose the job,” he says. “If printers are willing to do the work up front, they can create a working color management system that shows customers what they are able to do before they get into a difficult situation.”
Craig Tinkelman, CEO, Quaker Chroma Imaging, based in Moorestown, NJ, notes that dye-sub, “is not an exact process like offset or photo printing. Through experience, you learn how each variable interacts, which ultimately helps control color better. We print color swatches of frequently used colors on all of our everyday fabrics. When a client needs us to nail a color, we look at the already sublimated swatches and pick the closest color makeup to get the desired result. We then make the necessary changes and re-download to print.”
The Match GameMany factors affect the final look of a dye-sub project—the RIP, printer, ink, transfer paper, fabric, coatings, or environmental climate. For example, the heat involved in the transfer process effects the ink, notes Gerry Rector, associate director, Neenah Paper, Inc. “The color may shift slightly. You have to know what will happen with your printer. A lot of folks are very surprised that there is a color shift when heat is involved.”
To achieve a close-to-perfect match with dye-sub, consistency across all variables in the process must be met. “If variables change, different results occur. Fluctuating temperatures and transfer times force things to change,” states Francisco De Brito, color services supervisor, Mimaki USA, Inc.
One of Conde Systems, Inc.’s areas of expertise is color management. “A majority of people we run into are in very poor shape,” notes David Gross, president, Conde. “A good portion of the clients we help did not buy equipment from us; they have hand me downs.”
Gross says color management should begin with linearizing the printer. “Linearizing simply means that when I ask for ten percent, I get ten percent. If your device is not linearized, it will be difficult to achieve consistent results.”
The next step is to use a good color management package, print and read test patches and swatch charts, and build an ICC profile. “In addition, you have to set ink limits,” he says. “Your paper is only capable of handling a certain amount of ink, and if you exceed that maximum ink capacity the ink will run on the paper.”
Rob Repasi, VP, TexPrint Sublimation Paper Group, Beaver Paper, notes that some PSPs encounter problems when they mistakenly apply extra ink to achieve stronger color. The result is cockled sublimation paper, head strikes, and other problems. “Many people historically believed that applying more ink onto paper meant more color. Compared to ink from a few years ago, today’s ink is good enough that extra layers are not needed,” he explains.
Much of color management’s success comes from skilled production staff. “We try to make the most forgiving paper. However if our customers need help, we have a technical staff on hand,” says Guy Spinelli, president, SpectraJet.
“Most issues have to do with the need for color training. Shops with an employee who specializes in color software understand how to communicate with the customer, which results in fewer problems,” expresses Slep.
Color management occurs more on the transfer than fabric side. “Fabrics are very similar. They’re not treated or coated and are 100 percent polyester. We create profiles for the paper,” explains Paul Glynn, VP of operations, Portland Color. The Portland, ME grand format print specialist uses ONYX Graphics, Inc. RIP software and X-Rite, Inc.’s Monaco ICC profile creation software. For printing, the shop utilizes a Hewlett-Packard Scitex XL1500 with solvent ink.
Portland Color does not recreate its ICC profile often. “If the manufacturer makes a change to the ink or if the paper changes, you have to do it. There were more changes in our first two years of operation. We experimented with different transfer papers and tweaked the coating on the papers to work better with the ink. Before we settled on one, we always had at least two papers going.”
Dye-Sub Ink SpotlightProfiles, operators, and printing tools determine the color and transfer quality of dye-sub work. Here, we spotlight the dye-sub process and look at the way inks can affect color.
In traditional dye-sub transfer, graphics are first printed onto a transfer paper with a piezo-based wide format printer. Then they are sublimated onto 100-percent polyester fabric using a heat press. Another dye-sub option is direct printing, where graphics are printed directly onto a fabric with a special coating that accepts the ink.
Dye-sub inks are solvent-, oil-, or water-based. Ink type is chosen based on the printer and application. “Water-based inks are predominantly used in wide and small format printers, where oil- and solvent-based are typically used in wide and grand format,” explains Hilord’s Slep.
Aqueous ink carries a dye in water. If the ink has a lower concentration of dye, it requires heavier ink coverage to achieve the desired color. Too much water ultimately leads to oversaturation. “Water is the main cause of production losses and defects as it makes paper cockle and increases dry time. These issues are usually addressed with heavier, more expensive media and climate control in the print room,” explains Labella.
ElvaJet ink is the newest water-based ink from US Sublimation. “The advanced formulation allows for higher than usual dye loads and offers very practical advantages in the production process by reducing the amount of water needed to deliver the dyes.” In addition, US Sublimation offers UVMax, a four-color aqueous ink set with UV stability, making it ideal for applications requiring enhanced lightfastness.
Mimaki’s Sb52 water-based inks feature a new formulation with higher density and improved color characteristics. The ink is available in blue, magenta, yellow, light blue, light magenta, deep black, and normal black. “Designed for our printers, we’ve witnessed a good response in regards to color gamut,” states De Brito. “The price is also very competitive.”
Oil- and solvent-based inks are often used on 100-inch printers or wider. “These printers use oil and solvent inks due to the amount of ink and the surface of the print that is applied. They require a faster evaporation to take advantage of the speed and width,” shares SpectraJet’s DeWyngaert.
DeWyngaert explains that both oil- and solvent-based inks have a distinct advantage because they do not contain water as a carrier. “The paper surface is not shocked with a high amount of water over a short period of time,” he adds.
Solvent ink is sometimes looked at negatively from a “green” aspect, although it certainly has its place in printing. “Solvent offers a lot of advantages in terms of the speed because it dries faster than aqueous ink. It also sublimates better, has a higher outdoor durability, and better waterfastness,” states Steve Emery, manager, ink sales and marketing, EFI. The company offers UltraTex solvent dye-sub inks, as well as FabriVu oil-based dye-sub inks.
A disadvantage of solvent ink is the presence of volatile organic compounds (VOCs) and emitted odors. However, Slep notes, “You can easily add a carbon filter to your printer and capture 99.9 percent of VOCs.” Hilord, which manufactures dye-sub solvent ink in addition to oil and aqueous, reclaims and recycles solvents during the manufacturing process.
Color AidFrom uniquely formulated inks, to consistent transfer papers and support services, manufacturers help achieve desired color with dye-sub. Distributors offer color management support along with a full solution from paper to ink.
The availability of a wide range of colors is an important feature of US Sublimation inks, according to Labella. Their LFP series offers three different blacks. Standard black is often used in textile sample production to match the shade of black typically obtained with the final screenprinting process. The Ultra Black option is a pre-built black that reduces the need to create the black in CMYK, while maintaining neutral grays and gradients. The third LFP black is specially formulated to reduce metamerism, when two colors look the same under one light source but not under another.
Hilord uses colors closer to the true four-color system, that is, not a pink magenta. “This allows the printer to obtain real colors, especially in the grays and skin tones,” says Slep.
Mimaki offers proprietary color management software called Mimaki Profile Master II to aid customers in consistent color across Mimaki printers and applications.
Dye-Sub ToolboxDye-sub opens a world of possibilities for the creative marketer, designer, or PSP. Projects can be washed, backlit, and applied to a host of substrates—from fabric to glass.
Know what to expect from the dye-sub variables—ink, printers, transfer paper, and heaters. Keep humidity under control and tools consistent. Create profiles and train production staff. These steps provide a competitive advantage in dye-sub printing.
Mar2010, Digital Output