Digitally Printed Murals

Daffy Duck wallpaper and the Sistine Chapel frescoes are murals. Describing both on equal terms may seem bizarre, but, because of modern technology, images on walls have new form and definition. Large-format digital imaging plays an important part in this change.

In fact, digital technology propelled this art form from pink-toed wall cherubs to large, bold and colorful renderings of art and information. Right now, typically, museums and businesses both use murals, especially those printed on fabric, to announce events, ideas or, at least, attract attention.

Today, most artists, designers, and sign- and banner-makers use large-format digital-printing processes to produce murals. In addition to easing production, digital technology has also increased the demand for murals. With this technology, sign-makers can easily produce large, full-color prints on fabric (or any sign-type substrate) for presentation as a temporary or permanent mural.

You might describe some of these modern murals as signs or banners — conversely, you might describe some signs and banners as murals. Because of new print techniques, substrates and fabrics, the definition is hazy.

A classic example is that Planet3 Imaging, Boulder, CO, recently produced a series of hanging photographic murals for a three-museum western history exhibit in Denver. With the same technology, the company printed construction murals for renewal projects at Boulder s Crossroad Mall. The construction murals include text; they block the entryway to construction areas. Further confusion arrives when some marketers describe 3Ms Scotchcal floor graphics as horizontal murals.

Of course, a certain amount of definition is necessary, but, frankly, the best bet may be to let your customers describe what they want: sign, banner, mural. The main objective is to determine how to make and sell murals. This may be easier than you first think. Conceivably, you presently own the tools — computer-aided sign-making (CAS) software.

Basic CAS software is more than suitable for designing information murals, and newer CAS programs from CADlink Technology Corp. (Ottawa, ON, Canada) or SA International (Philadelphia, PA) include extensive color-imaging tools. Other software, such as Adobe Photoshop or its lesser rival, CorelDRAW!, may add to your design kit. If you do not own or want to buy digital print equipment, you can simplify production by contracting with an outside digital service bureau.CADlink Technology Corporation, Scanvec Amiable

Also, because you ll find varied processes and techniques, you ll want to carefully examine the project, its uses and the indoor or outdoor life span required of the final print.

Selling digital murals

You can carry the museum-mural concept over into retail outlets — diorama-type photographs of young softball players on a shoe-store wall, for example, or a graphically strong mural on the outside of a mall announcing a craft fair rather than a Picasso exhibit. Also, many tradeshow displays now contain digitally printed mural back walls.

Professional sign-sales representatives tend to look down on the digital market just as they do cut-vinyl signs. Sign-makers at the Intl. Sign Assoc. (ISA) Educational Conference in San Diego, CA, recently discussed this dilemma, suggesting that owners pay higher commissions on digital-print jobs or hire and train specialized digital sales people.

On the average, digital inkjet prints sell for $8-12 per sq. ft. Add dollars for laminating, special coatings and unique substrates; add, too, for computer work — scanning, special preparation and file transfer.

File transfer, according to several speakers at DigiGrafix 96, (an educational conference held in Dallas, TX, in July), has become a coveted craft. Designers who understand and transfer computer files, according to several DigiGrafix speakers, have a successful future ahead.

Repeat work is the primary goal in digital-imaging sales. It s also the success key because although digital prints can be singularly inexpensive, multiple prints, of course, are better. As with any manufacturing process, the cost goes down as the quantity goes up.

Types of digital printers

Because other issues of ST and its sister magazine, The Big Picture, have extensively covered the digital-print field, we re presenting only an overview of the technology here.

Thermal-transfer printing produces uniform color densities; industry connoisseurs rate the image quality at fair-to-good. Using wax or resin ribbons, thermal-transfer print machines image CMYK or spot colors directly on paper, vinyl films or other graphics substrates. The spot-color ribbons tend to have good opacity, and process colors have uniform color characteristics. Also, thermal-transfer technology provides good-to-excellent fade and moisture resistance; prints on water-resistant substrates are outdoor-ready for extended periods without lamination.

At this time, most machines will print on adhesive-backed vinyl and a selection of other materials. Once images are printed on vinyl, you can simply apply the substrates in the same manner as computer-cut vinyl.

Inkjet printers are comparatively inexpensive, reliable and easy to use. Inkjet-printed graphics exhibit high color intensity, consistency and image quality. 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. Unlaminated, inkjet prints may suffer from fade and moisture damage, although more than several companies have introduced UV- or water-resistant inks over the last year. 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. 3M also has a proprietary inkjet system in its Scotchprint family.

Electrostatic printing produces a relatively lightfast image. However, fresh-off-the-press, electrostatic prints are not resistant to moisture or mechanical action. Once Scotchprint™ images are processed, however, the prints carry an outdoor-use warranty. Although electrostatic equipment is expensive, prints on various substrates are available through numerous service bureaus.

Electrostatic images require some form of encapsulation — usually lamination — to achieve moisture and abrasion resistance. Also, users can transfer the images to other graphic substrates, such as adhesive-backed vinyl, to expand the range of applications. Several new processes have short cut these standard procedures, including 3M s ES media series 3651-10 adhesive-backed, direct-print vinyl film and Raster Graphics 5th ink-station varnish application.

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.

Super-size airbrush Often referred to as super-size printers, these behemoths of large-format printing are high in image size and machine cost — some super-size machines list for more than $1 million. 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.

Individual characteristics of grand-format machines vary with the machine and manufacturer — the prints, however, have similar uses. And, although grand-format processes vary, the general classification of these machines is airbrush atomizing type systems, meaning pressurized air displaces the paint or ink rather than thermal, catalytic or electromagnetic action. Notice, too, that the preceding sentence includes the word paint. Grand-format, because of its unique delivery systems, often allows use of inordinate media, including acrylic polymers (paint), dyes or inks.

Grand-format also offers the ability to print on various substrates, including, for example, canvas or carpeting. Outdoor life of a grand-format-produced print varies because of the diverse machines, substrates and medias. Belcom s (Chicago, IL) Errol Doris says to expect 10 years outdoor life from his company s Michelangelo printed acrylic paints. Billboard materials, conversely, seldom need to last more than six months.

Obviously, before bidding a job, you ll want a clear understanding from your customer as to what is expected, and a clear agreement with your materials providers as to how long the print will last.

Dye-sublimation images, first printed onto a special paper by a modified electrostatic or inkjet printer, then heat-transferred to a synthetic fabric, result in a soft, flexible print. Xerox ColorgrafX and Paedia Corp., San Francisco, CA, have developed a dye-printing electrostatic system. Cactus Systems, Chino, CA, also offers electrostatic and inkjet systems for dye sublimation printing on fabrics.

Substrates, fabrics

Any substrate suitable for sign applications is suitable for a mural. Cautions are weatherability and performance life. Applications relate to the substrate and media, meaning, for example, that murals printed onto adhesive-backed vinyl will easily apply to smooth surfaces, but certainly not bricks. Excepting thermal-transfer images, digitally printed substrates require more cautious handling than cut-vinyl signs because the surface may easily scratch. Most experienced installers recommend you use new squeegees with a scratch-proof covering for most applications.

It s important to remember that the final word on printable fabrics and their compatibility with digitally printed vinyl or inks must come from both suppliers — image and substrate. You ll want to know about printability and performance issues before starting a project.

Coated nylon is among the popular fabrics for banners or murals for interior or short-term outdoor use; topcoated nylon is suitable for inkjet-type inks and has a general outdoor life-span of six months. Topcoated vinyl, chosen for some electrostatic transfer methods, is also suitable for sign enamels and grand-format systems acrylic paints.

Polyethylenes, inexpensive and acceptable for indoor banners or murals, mural applications or very short-term outdoor jobs, are available in one- and two-sided versions; the product accepts adhesive-backed vinyl. Polyolefins — the best known are DuPont s Tyvek® brand materials — and other blends are suitable for long-term outdoor use. Some manufacturers treat these with inkjet-receptive coatings.

Amiable Technologies, Inc., offers a polyester film suitable for indoor banners or murals and four-mil white VinylGloss suitable for outdoors when laminated. Both have an inkjet-compatible topcoating. The flexible-face materials used for illuminated awnings and electric signfaces rate best for high-test digital-imaging uses. Cooley Sign Systems, Pawtucket, RI, manufacturers CoolFlex™ frontlit billboard substrate, printable on both sides, and Coolthane™ flexible signface materials for high-strength needs.

Most print-machine manufacturers, including Hewlett-Packard and |2127|, provide materials and inks for general graphic applications. Xerox, for example, offers a line of media and inks for its new VivagrafX inkjet printer. Rexam Graphics, South Hadley, MA, offers its Artist Canvas material for interesting inkjet print images. Kapco Graphic Products, Kent, OH, too, offers a topcoat canvas for inkjet prints. Other material s sources — Tekra Advanced Technologies Group, New Berlin, WI; Avery Dennison Graphics & Reflective Products Div., Painesville, OH; Flexcon, Spencer, MA; Best Buy Banners Co., Riverside CA; Océ USA-Bruning, Itasca, IL; and Spar-Cal™, Molt, MN — also specialize in materials suitable for murals.Encad Inc., KAPCO, Avery Dennison Graphics Division, FLEXcon, Océ North America Inc.