The water-based nature of inkjet inks requires that substrates be treated with a receptor coating to achieve ink adhesion. Also, in most cases, manufacturers recommend lamination. Some manufacturers, in fact, warranty the outdoor life of inkjet prints. An interesting example here is that 3M and LaserMaster, Eden Prairie, MN, recently announced a supply agreement that includes warranted, outdoor inkjet materials, inks and adhesive-backed films. M also has a proprietary inkjet system in its Scotchprint family.
Electrostatic printing produces a relatively lightfast image.
Although electrostatic equipment is expensive, prints on various substrates are available through numerous service bureaus. Also, users can transfer the images to other graphic substrates, such as adhesive-backed vinyl, to expand the range of applications. Rexam Graphics, South Hadley, MA, offers its Wearcoat product that transfers an integral coating along with the digital image, eliminating the overlaminate film. Seal Products, Cottage Grove, WI, offers its Gardian 180 system to reduce the cost of electrostatic consumables. Originally intended for billboard imaging and long-distance viewing, recent design changes and subsequent in resolution improvements allow users to prints banners, murals and numerous other displays.