New applications of graphic elements are a species of fabric architecture that allows the most colorful and visual creativity. Environmental graphics fabricators constantly look for new ways to grab the eye or fill a space.
The key to selecting the proper fabric is knowing the function a banner or graphic element is to perform. Other factors include longevity, color, appearance, design graphics, acoustics and handling.
How long should a banner remain up? What conditions will it face? The answers depend on the type of graphic desired (interior, exterior, atrium, streetlamp, etc.). Exterior banners are at the mercy of sun, wind and precipitation. With interior banners, flame retardancy, or the fabric’s porosity to pass water from a sprinkler system, becomes important.
In the past, specifiers believed banner fabric didn’t come in many colors and that banners should be designed using no more than two or three colors. Today, banner fabric comes in a variety of colors, including the newest, most up-to-date hues (although not all colors are available in all fabrics). As a result, many colors can be used on one banner.
Should the graphic hang straight or float in the breeze? Heavier materials will hang well but will not flap much. Thinner materials may wear out faster by excessive flapping. Should the graphic be translucent or opaque? Generally, the greater a material’s translucency, the less its strength and stability.
Design graphics are also a consideration. Heat-transfer films, sublimation/transfer print, heat-sealed inset fabric, sewn-in inset fabric, eradication, pressure sensitive vinyl, silk-screening, digital printing and hand painting often are used to decorate banners. Not all methods work well with all fabrics, so check its fabric compatibility before using a particular graphic method.
Fabrics absorb sound. Sound waves’ energy is used up moving the fibers; in the friction that movement creates, the sound volume drops. The amount a banner absorbs depends on the weight of the fabric, the distance from a wall surface and how many folds the banner fabric has.
Adding banners can help improve a space’s acoustics, particularly in hard-surfaced, high-ceilinged areas. Banners also can work in conjunction with fabrics used for acoustical panels, speaker covers or wallcoverings for additional sound absorption. When improving acoustics is a banner’s primary reason for existence, a nonporous fabric can be specified to enclose a core of fiberglass or similar sound-absorbing material.
Handling also varies among fabrics. Look into whether the fabrics can be heat sealed (with or without seam tape) or sewn, their shrinkage and stretch factors, and whether cleaning agents, spec sheets and technical manuals are available.
Once you’ve answered the preceding usage questions, you can select a fabric. Each banner fabric described here, starting with the most commonly used materials, offers its own combination of properties and its own advantages and disadvantages.
Laminates offer the benefits of two or more materials in one. These fabrics are constructed by sandwiching polyester, nylon or fiberglass scrims between two layers of vinyl. Technically, they are formed when the scrim is calendared between two layers of thermoplastic film, but generally they are manufactured by applying heat and pressure and including an adhesive layer between the film and scrim layers.
The scrim provides tensile and tear strength, plus dimensional stability. The vinyl offers a smooth, uniform surface for printing graphics. It’s relatively easy to make banners from laminates because they can be sewn, heat-sealed or radio-frequency (RF) welded. What’s more, most laminates meet the strict requirements of the California State Fire Marshal. They can be used for nearly any type of graphics, except where lightness and translucency are desired. However, they do not have a soft hand nor drapability, and come in limited color choices.
From a distance this material appears to be solid vinyl, but up close its open-weave design becomes apparent. Meshes, or a combination of solid and mesh fabrics, make a good choice when wind loads are a major factor because wind passes through their open weave, effectively reducing the banner’s wind load. For instance, using a weave that is 30% open essentially reduces the banner’s area by 30%, and thus its wind load by the same amount.
Polyester fabrics are woven or knitted polyester fibers that have been coated or treated for durability, smoothness and printability. The manufacturer adds chemical compounds to provide pigment, flame retardance, and UV, water and mildew resistance to the liquid vinyl coating. The coating is applied to the polyester scrim, then cured by passing through a heated chamber. Vinyl-coated polyesters most often are used to create lightweight banners printed on one side.
This dimensionally stable fabric can be used for interior or exterior graphics. It comes in a wide range of colors and accepts silk-screening, appliqué, and hand painting.
Nylon has most of polyester’s advantages and comes in a variety of weights. The translucency and drape of lighter nylons make them popular choices for interior banners. Heavier weights often are used for outdoor applications. Also, nylon and polyester are the fabrics most typically used for flags. Nylon colors can be combined to create new colors. A very versatile fabric, it accepts printing, appliqué hand painting and vinyl film applications.
Acrylic offers the aesthetics of cotton but is resistant to UV light, mildew and water.Weaving makes the acrylic fabric highly breathable, so hot air and moisture will not be trapped.
In solution dyeing, color pigments are added to the acrylic fibers while the fibers are in a semiliquid state. As a result, the color becomes an integral part of the fiber and, unlike piece-dyed acrylic, won’t wash out. Solution dyeing reduces fading and deterioration due to UV exposure and is available in more than 100 solids, stripes, and patterns. Guaranteed to hold its color for 5 years, it can create bright, long-term outdoor graphics.
Although modacrylic shares many of acrylic’s characteristics, it has differences, including increased flame resistance and heat sensitivity.
Spunbonded polyolefin fabrics look and feel much like paper. They are lightweight, weatherable and low-cost. They typically are used to create short-term, indoor/outdoor graphics.
Unsupported films, such as polyethylene or vinyl sheeting, are lightweight, inexpensive plastics without any fabric reinforcement (scrim). Their smooth surfaces make them suitable for screenprinting. Be aware, however, that they have a finite shelf life as graphics and should be specified from recent inventory.
Canvas and drill cloth
Canvas and drill cloth are natural (as opposed to the others, which are synthetic) fabrics. They tend to last fairly well for indoor and outdoor applications and generally are less expensive than synthetics. Despite their lower cost and relative familiarity, canvas and drill cloth haven’t been used much in the industry in a long time. Canvas is less UV-resistant than synthetics, and some believe it is less capable of holding a variety of bright colors. In addition, synthetic options are more economical, have fewer wrinkles and are easier to print.
Much of the graphics world continues to spin around nylon and vinyl, but bannermakers are experimenting with other, more exotic materials, primarily for interior uses. Silk, wool, spandex, linen, satin, nylon netting, metallics and others have emerged as alternatives. Unusual fabrics often are used for their visual appeal and for clients looking for something different, especially for use in retail or commercial applications.
Functional concerns also can drive nontraditional fabric selection. Strict flammability codes may dictate that the fabric attached to a ceiling be porous enough to allow water from a fire sprinkler system to pass through it, in which case a nonwoven made from spun fiberglass cords may prove the best choice.
Some designers liken metallic fabrics, such as lamé, to “liquid metal.” Metallized refers to a substrate with a thin covering of metal, often silver, aluminum or a copper alloy. The substrate may be polyester, nylon or, when flame retardancy is required, modacrylic. Handling of the fabric — sewing, laminating or other processes — depends on the nature of the substrate.
Warp-knit fabrics are gaining interest for both indoor and outdoor applications because, if ripped, they resist unraveling at the edges. Some graphic designers even are playing with spandex to give their creations a distinctive, tensile-structure shape.
Useful in outdoor flags and graphics, knit polyester has yet to penetrate much of the North American market because it requires special automated printing equipment. After banner manufacturers have made the initial equipment investment, the material becomes inexpensive to print. It is durable and the knitted construction allows air to pass through, rather than blocking or catching the wind. The polyester is longer-lasting and less expensive to manufacture than nylon, which has been the fabric of choice.
Satin organza, polyester chiffon, silk taffeta and other sheer fabrics are more commonly associated with the bridal-wear market than with banners and flags. Similarly lightweight ethereal materials have found a niche, though, with retail store displays and in the exhibit hall market. When printed, sheer cloths seem to disappear, leaving only the fluttering graphic readily visible. Many sheer fabrics will accept dye sublimation if their polyester content is over 20 percent. Fabrics are preshrunk if dye sublimated.
Other nontraditional fabrics that have found their way into graphics include:
- polyester twills
- uncoated polyester
- flame-retardant satin
- nylon netting
Graphics need not even be fabric, or at least not all fabric. Metal and plastic pieces have been made into or sewn onto banners for visual variety. Chain mail, cloth tassels, wooden ornaments, foam, lighting and many other materials have been incorporated into banners.
One way to ensure choosing the most appropriate fabric for a particular job is to work as closely as possible with the creative people who design and manufacture banners. They not only know what works best in a given situation, but keep their eyes open for new fabric possibilities.