Managing colours
Accuracy and efficiency in textile printing also depend on colour management, i.e. ensuring inks will achieve the desired graphic appearance on the final substrate.
Textiles developed for garments have proven well-suited for a wide range of wide-format graphic applications, including wallcoverings. Photos courtesy Hitoshi Ujiie
“Colour management is important for translating a graphic onto a textile, but some people aren’t doing it yet,” says Ann Laidlaw, textile supply chain manager for X-Rite, which provides spectrophotometers and software for colour profiling and management. “A colour in cotton, for example, is different from one chemically bonded in thermoplastic. Colour standards need to be communicated throughout the process. Visual evaluations must be controlled and consistent.”
The sign industry appears particularly well-poised to deal with such issues when diversifying its range of output.
“Sign shops taking on fabrics probably already have the right equipment for colour management,” says Brian Ashe, an X-Rite technical consultant to the global digital supply chain. “Each material requires its own profile and each colour has its own ‘fingerprint,’ but in today’s world of digital communications, wide-format shops are getting accustomed to having to print the same graphics on five different substrates. We’re seeing a lot of crossover.”
Material decisions
Substrate selection is another important factor, as various ink chemistries are developed for optimal use with specific products.
“You can use dye-sub on polyesters, for example, or latex inks on cotton and canvas that cannot be heat-transfer printed,” says Designtex’s Siegel.
Textiles are available for a wide range of applications, including window displays, POP graphics, wallcoverings, murals, outdoor and indoor banners, flags, backlit graphics, trade show displays, table drapes, roll-up banner stands, fine art reproductions, theatrical displays, maps and custom upholstery.
Colour management is important to ensure inks will achieve the desired appearance on various fabrics and other materials.
“There are hundreds of types of polyester, one for every purpose in the book,” says Gardino. “If you go to a garment district, you’ll find any kind of fabric you need is already out there. You can even find pool-table felt that’s been tweaked for digital printing!”
“Not much has changed in the processing of textiles in the past 50 years or so,” says Richardson. “The technology breakthroughs have been on the printing and ink side, running the gamut from eco-solvent to ultraviolet-curable (UV-curable) to latex to dye-sub. That technology affects substrate choice. If you’re printing direct-to-fabric, you need to buy pretreated textiles. The pretreatment is like a bath for the material. The excess dip is rolled off and you get a saturated fabric, though not heavily so. These pretreated textiles may only represent 10 per cent of the variety that heat-transfer printing can use.”
As such, research and development (R&D) efforts continue to respond to printer technologies and other elements that can affect how fabric graphics are produced.
“The fabric chemistry challenge is to achieve maximum colour output while still ensuring fire retardancy,” says Richardson. “You’ve got to hit both targets. Some fire-retardant coatings can make the material stiffer, yellower and less bright.”
Health and environmental issues are also coming to the fore, with customer requests reflecting sustainability concerns.
“We’re getting away from bromine because of its health impact,” Richardson says. “The Canadian market is also a little more sensitive than some others to the environment, especially when serving customers like municipalities that display banners along their streets. There is a lot of call for recycled fabrics.”
“Fabrics are an environmental upgrade from vinyl, but they’re also a quality upgrade,” Siegel suggests. “They’re not just a way to replace vinyl graphics. They have their own tactile appeal and light beautifully. The industry is continuing to communicate that value to clients.”
With files from the Industrial Fabrics Association International (IFAI), Mimaki, Aurora Specialty Textiles Group, Designtex, the Center for Excellence of Digital Inkjet Printing for Textiles and X-Rite. For more information, visit www.ifai.com, www.mimakiusa.com, www.auroratextile.com, www.designtex.com, www.philau.edu/textiledesign/center.html and www.xrite.com.
