Ink types are generally best suited to select applications. For example, vehicle wraps are often produced with solvent, eco-solvent, or UV-curable ink due to the flexibility and durability they offer. For rigid work created with flatbeds, UV is popular, but most ink chemistries will work. Adhesion characteristics are important for difficult substrates such as acrylic, glass, and metals.
“Above all else, inks and other colorant technologies must be fit for purpose,” states Jeff Edwards, international product marketing manager, display graphics systems, Océ North America. This is determined based on either an application or a system perspective.
Ink characteristics, such as durability, color gamut, and flexibility are essential considerations when choosing the best ink set for a particular job. Steve Igoe, sales manager, North America, Bordeaux Digital Printink, suggests that a wide color gamut has no value without durability. This implies resistance to fading, weathering, as well as excellent adhesive and cohesive properties that strongly fix the ink to the increasing number of substrates available today.
Most importantly, inks must deliver rich and vibrant colors that make large format applications stand out. Color consistency is critical as customers want the assurance that logos and other banded items meet specific standards.
Water-based inks tend to be more affordable and provide environmental benefits. Both aqueous- and solvent-based inks can use both dyes and pigments. Heather Rockow, UV-curable sales manager, Collins Ink Corporation, explains that dyes provide a wide color gamut, but are not as lightfast as pigments. “Since water constitutes a majority of the ink formula, it tends to be cheaper in cost. It is a ‘greener’ chemistry as well,” she says.
Sawgrass Technologies Industrial develops a range of aqueous dye and pigment inks for the large format space, ideal for applications including indoor furnishings, outdoor furnishes, soft signage, specialty fabrics, and fashion and apparel.
Marabu North America, known for its solvent ink sets, launched its new water-based sublimation ink in February 2012. TexaJet DX-SHE is ideal for soft signage, flags and banners, sports apparel, fashion, and fine art prints.
Solvent Selling Points
Vehicle wraps are best produced using solvent or eco-solvent inks due to the fact that solvent inks become a part of the media, rather than sitting on top as UV inks do, comments John Kaiser, product marketing manager, inkjet inks, graphic systems division – wide format and specialty ink systems, Fujifilm North America Corporation. Flexibility, elongation, and color gamut all play a role in ink selection and solvent is influential in all of these areas.
Epson’s UltraChrome GS and GS2 technologies offer durable output for outdoor and indoor signage applications, vehicle wraps, and fine art. The inks offer a wide color gamut with the ability to print on coated and uncoated media. “Because this is a solvent-based ink, it has the ability to print on the vast majority of the solvent and signage media available that customers use today, including textile, vinyl, banner, backlit, paper, and even canvas,” states Reed Hecht, product manager, professional imaging, Epson.
Van Son Ink Corporation’s solvent and eco-solvent inks are designed specifically for popular large format applications such as vehicle wraps, backlit, wallcoverings, store graphics, point of purchase (POP), and banners. “Our solvent and eco-solvent inks offer the deep, rich colors needed for these applications. They also adhere and stretch well. Flexibility is an essential attribute for vehicle wraps as you need the ink to give when stretching around bumpers and complex curves,” notes Tom Sheehan, wide format ink specialist, Van Son.
Regarding the benefits of solvent/eco-solvent inks, Rockow explains that using aggressive or eco-solvents provide good adhesion to a variety of substrates. “The ink tends to cost less because the solvents are commonly available,” she adds.
INX Digital International Co. heavily promotes its eco-solvent EDX inks under the Triangle brand. These are optimized for use in printers utilizing Epson DX4 and DX5 printheads. They are available in one liter bottles and 440 and 220 milliliter cartridges.
UV-curable inks offer many benefits for large format printing. “Today’s UV-curable ink technologies efficiently address screen, offset, and digital applications and offer exceptionally wide media versatility with the ability to print on papers, film, self-adhesive vinyl, foam board, PVC, corrugated cardboard, and many other media types,” suggests Eyal Duzy, marketing segment manager, Scitex Industrial Solutions, Hewlett-Packard.
Kaiser says rigid display or POP graphics are the bread and butter of flatbed printers and as such UV tends to the ink choice. High printing speed and the ability to print and cure without lamination leads to lower unit costs. Additionally, while billboard printing utilizes a mixed bag of ink technology, he notes that a move to more woven PE materials has driven the market towards UV.
“We believe UV ink is the most universal ink available,” notes Larry Salomon, VP, wide format North America, Agfa Graphics. He says the ink’s flexibility is ideal for demanding conditions, including temperature or humidity fluctuations.
Rockow points out that UV provides adhesion to a variety of substrates from coated paper, plastics, metals, and ceramics. It does not contain volatile organic compounds, making it a greener chemistry. The inks cure very quickly so the printed object can be handled or applied immediately. “Because more people are using UV inks now than in previous years, the raw material costs are coming down,” she adds.
Ink Set Advantages
The type of ink used for a job is essential to its ability to perform in its final destination. Durability, flexibility, and color vibrancy are all important characteristics of ink, which are prioritized based on application. Certain ink sets are proven to perform better in certain conditions. Print service providers should weigh these concerns against customer expectations when deciding which ink set to invest in or utilize for a given job.