Why Are There So Many Types of Inks for Inkjet Printers?
If you’re confused by the enormous variety of inks and materials for wide-format inkjet printers, you’re not alone. Confusion about inkjet inks is widespread.
Today, hundreds of different models of inkjet printers are used in settings ranging from small offices, design studios, and retail stores to multi-national printing firms and industrial plants.
Before explaining the differences between aqueous, latex, eco-solvent, solvent, UV-curable, and dye-sublimation inks, let’s review the major types of inkjet printers and how they are used. This helps explain why so many different types of ink formulations exist.
The first wide-format inkjet printers used aqueous dye inks and were less than 60 inches wide. Early adopters included architects, engineers, and imaging experts who wanted to print large computer-aided designs (CAD), architectural renderings, and images captured by earth-observation satellites.
Since then, many different types of inkjet printers, ink formulations, and materials have been specifically developed to enable cost-effective, higher-volume inkjet printing on materials other than paper.
Specialized inks, printers, and materials have been developed for applications such as outdoor signs and billboards, corrugated packaging boxes, fabrics and wallcoverings, vehicle wraps and fleet markings, promotional products, and apparel. Images, graphics, and surface textures can now be inkjet printed directly to thousands of different surfaces and materials.
The different formulations of inks help dictate the look, feel, and durability of the prints in the indoor or outdoor conditions in which the prints will be used. For example, textile inks used for apparel must not affect the comfort of the garment yet be durable enough to withstand repeated washings. Inks printed on vehicle-wrap vinyls must be stretchy enough to conform to the contours of a car without cracking. Every application has a different set of requirements.
TYPES OF WIDE-FORMAT INKJET PRINTERS
Wide-format printers for use in offices, schools, stores, and studios typically range from 24 to 60 inches. The smaller models fit on countertops, workbenches, construction job-site trailers or sites with limited floor-space.
Most print-for-pay wide-format graphics companies use a mix of roll-feed, sheet-fed, flatbed, or hybrid wide-format printers that range from 63 to 126 inches wide. Print-for-pay wide-format shops also use digital cutting equipment and other finishing equipment that will convert the prints into sellable products.
Roll-feed printers use aqueous, latex, solvent, eco-solvent, UV-curable, dye-sublimation, or textile inks to print on different types of rolled materials. The type of ink used depends on whether the printer is used to print everyday documents and photos, outdoor signs, washable fashion or sportswear fabrics, durable textiles for signs and displays, or retail signage.
Flatbed wide-format inkjet printers handle large sheets of rigid materials. These devices typically use UV-curable inks.
Hybrid wide-format inkjet printers can handle either rolls of materials or sheets of rigid substrates. Most hybrid printers use UV-curable inks. But HP’s R2000 printer uses latex inks to print on rolls or rigid sheets.
OTHER TYPES OF INKJET PRINTERS
Direct-to-object inkjet printers use UV-curable inks to print directly onto three-dimensional products such as water-bottles, glassware, phone cases, or golf balls. Some benchtop models are designed for use in small spaces. Higher-speed single-pass models are built for use in manufacturing plants. Companies that make direct-to-object printers include Roland, LogoJET, Direct Color Systems, Engineered Printing Solutions, Xerox, and Heidelberg.
Direct-to-garment printers use water-based DTG inks to print images, text, and graphics directly onto cotton and cotton/poly T-shirts, tote bags, and fabrics for home decor items. Smaller models by companies such as Ricoh, Epson, Brother, Roland, and AnaJet are designed for use in retail stores, event venues, in-plant print shops, and sign shops. Faster devices from Kornit are designed for high-volume print-on-demand centers such as Amazon or Fanatics.
Production inkjet presses are used to print thousands of books, magazines, billing statements, catalogs, labels, and packaging. Many production-inkjet printers use inks that can print on the coated papers traditionally used with offset printing presses. Some production inkjet presses water-based inks. Some (such as the AccurioJET KM1) use UV-curable inks.
Industrial inkjet printers are engineered to output designs onto specific types of substrates, such as textiles, corrugated cardboard for packaging, ceramic tiles, glass, wallpapers, or wood used for floors, doors, and furniture.
Here’s a quick run-down on the key differences in the types of inks used in inkjet printers.
This category of inks uses water to carry different types of colorants (dye or pigments) to the surface of the printing material (inkjet media).
Dye inks use colored dyes that dissolve into the water.
Pigment inks use tiny particles of color that remain suspended in the water.
Aqueous inks are used to print text, graphics, or line drawings on inexpensive uncoated and coated bond papers used in offices and schools. They can also print on specially coated photo and art papers, proofing papers, canvases, vinyls, display films, window-graphic films, and backlit films. The coatings on these materials help control the performance of the ink droplets on the surface of the print.
Neither dye or pigment inks are totally waterproof.
Dye inks are more susceptible to fading and water damage, but are fine for prints that will be used in dry, indoor environments. Lamination or clearcoating is required to protect large-format dye-ink prints from water, humidity, and prolonged exposure to UV light.
Pigment inks have a higher level of resistance to fading and water than dye inks. Large-format pigment-ink prints on weather-resistant materials can be displayed outdoors for a few months without being laminated. Pigment inks printed on archival art and photo papers can last for generations when they aren’t displayed in direct sunlight for long periods of time or submerged in water.
Freedom Paper’s website has a separate category for HP PageWide XL pigment inks. These aqueous pigment inks are specifically designed for use with HP’s high-speed “fixed-array” printers in which the printheads span the width of the paper and apply all colors as the inkjet media makes a fast, single pass beneath the printheads.
Because the inks for these high-speed printers must dry instantly, the media for “single-pass” PageWide printers is manufactured differently than the media originally developed for traditional “multi-pass” inkjet printers in which the printhead moves back and forth across the paper. Papers for PageWide XL printers are manufactured with additives that keep the pigments close to the surface.
Many inkjet materials “optimized for PageWide inkjet printing” will work with the aqueous dye or aqueous pigment inks on legacy models of aqueous inkjet printers. But they won’t necessarily produce the same level of image quality as inkjet media that was coated specifically for traditional aqueous dye or pigment inks.
The first manufacturers of aqueous inkjet printers included HP, Canon, Encad, Colorspan, Kodak, Roland, Mimaki, and Mutoh. Some of these companies have been acquired or have moved on to different types of inks. Companies that currently make aqueous wide-format inkjet printers for office documents, photos, and graphics include Epson, HP, Canon, and Ricoh.
SOLVENT and ECO-SOLVENT INKS
These inks use solvents with volatile organic compounds (VOCs) instead of water to carry the pigments. There were originally developed to print outdoor-durable, unlaminated signs on flexible, uncoated vinyls. The original “hard solvent” inks were formulated to eat into the surface of the vinyl for a lasting, waterproof bond.
Solvent inks provide exceptional durability without the need for lamination or protective clearcoats. But the print-shop environment must be properly ventilated so that employees aren’t exposed to harmful fumes.
Eco-solvent inks use milder solvents that don’t require extra ventilation in enclosed spaces.
Solvent inks produce prints that are lightfast, waterproof, and scratch-resistant. Solvent inks are used to produce outdoor traffic signs, vinyl banners, fleet markings and vehicle wraps that will be displayed outdoors for years. If the graphics will be exposed to road salt, dirt, and repeated car washes, a laminating film is applied to add protection.
Eco-solvent inks can be used for shorter-term vehicle graphics and outdoor signs as well as interior signs, decals, wall murals, and indoor and outdoor art. Decorative art printed with eco-solvent inks on a coated canvas doesn’t require a protective varnish or clearcoat to remain resistant to fading or abrasion.
This category of inks is sometimes referred to as “durable aqueous” inks. In these water-based inks, the pigments are carried by latex or resin-based polymers that bond to the substrate after passing beneath radiant heaters.
HP developed Latex inks as an environmentally friendly alternative to solvent and eco-solvent inks for unlaminated signs that need to last three years or less outdoors. Ricoh and Mimaki also make wide-format inkjet printers that use latex inks.
Latex inks are used in a wide range of applications, including outdoor signs, wallcoverings, durable fabrics, backlit signs, canvas prints, and indoor banners and signs. The first latex printers were roll-to-roll printers. But HP recently introduced latex-ink printers that can handle rigid substrates for signs and décor.
These inks have chemistries that “cure” to form a rigid film when exposed to controlled intensities of UV light. The ink doesn’t evaporate when exposed to heat. Nor does it sink into the substrate.
UV-curable inks can print on a huge range of coated and uncoated materials, including wood, furniture, metals, plastics, and sign boards. UV-curable inks and clearcoats can be jetted in layers to create textured surfaces or Braille lettering.
The first generation of general-purpose UV inks worked best on rigid substrates and other non-stretchy banners and signs. But with advances in UV curing technologies and ink chemistries, UV-curable inks are now used for specialized printing requirements such as thermoforming or printing on ceramics, glass, acrylics, wood, three-dimensional objects, fabrics, standard offset-printing papers, and other flexible materials.
Canon’s “UV-Gel” technology uses a UV-curable ink that gels on contact with the print surface to improve image quality and boost production speeds. It reduces the amount of ink required to produce a good image.
OTHER TYPES OF INKS
Dye Sublimation Inks are different from the aqueous dye inks described above. Dye-sublimation inks become gases when subjected to heat and pressure. When the ink becomes a gas, it fuses beneath the surface of a polyester fabric or polyester-coated item to form a design that feels like an integral part of the decorated object. It doesn’t feel like a print. Nor does the print require lamination to resist damage from water, humidity, abrasion, or chemicals.
Most dye-sublimation inkjet printing involves printing the image in reverse on a specialized heat-transfer paper, then pressing the printed paper to the fabric or object in a heat-transfer press.
Dye sublimation inkjet printing is used to create fabric signs and trade-show graphics, fashion apparel, sportswear, promotional products, and photo gifts. Dye-sublimation inks are also transferred to polyester-treated rigid substrates to make durable wall art, tabletops, or floor tiles.
Textile inks are designed to print on the many different types of washable fabrics used in curtains, sheets, T-shirts, and other types of apparel. Wide-format inkjet printers designed for textile printing are built differently than the versatile wide-format inkjet printers that can print on coated, durable fabrics for soft signage, flags, and trade-show displays.
You can see the full range of inkjet printers for all types of commercial and industrial applications at the Printing United 2019 expo in Dallas, TX from October 23 to 25.
OUR HISTORY IN THE WIDE-FORMAT PRINTING MARKET
In 2002, Freedom Paper set up an e-commerce website to sell rolls of wide-format inkjet papers to architects, engineers, builders, woodworkers, surveyors, landscape architects, design studios, government agencies, utility companies, copy shops, in-plant print shops, and office customers. A pioneer in B2B e-commerce, we helped make wide-format printing more accessible to business users throughout the United States.
Seventeen years later, we continue to serve our business, education, copy shop, and government-agency customers as well as the many photographers and artists who use Canon, Epson, and HP aqueous-inkjet printers to make their own photo and art prints. Although we specialize in selling materials for aqueous inkjet printers, we also sell materials up to 60-in. wide for the compact, entry-level latex, eco-solvent, and UV-curable printers found in sign shops and in-plant print shops.
If you have never purchased wide-format inkjet bond papers, photo papers, art papers, display films, or sign vinyls for your office or studio, our experienced staff can help you make the right choice for your application.
Chat with us online at www.freedompaper.com or call us at 855-310-3335.