By Melissa Donovan
Marketers recognize the appeal of a textile promoting a brand or serving as a color backdrop in a retail space or consumer-focused environment. Arguably, the printed graphic is only as good as the accessories or tools used to hang it. One of the more popular options to display fabric is a light box frame.
No stranger to print, light box frames were traditionally used with clear plastics and thick films, printed digitally or in the past via lithography. Over the years, the architecture of the light box evolved in dimension, usability, and lighting. As such, new frame extrusion technologies, such as silicone edge graphic (SEG) frames are available.
The type of fabric used in light boxes depends on physical properties such as white point and stretchability as well as the direction of the lighting and the method in which the graphic is printed. The correct combination of media and frame yields a crisp, clear graphic that pops.
Changes in Light Box Structure
The increased popularity of fabric signage affects the components—dimension, usability, and lighting—of light boxes. Evolving to accommodate textiles, the newest extrusion technologies focus on the nuances of this substrate.
Carrie Harvey, senior marketing specialist, Stylmark, Inc., explains that many traditional light box signs were limited in size due to the transparency film graphic and the acrylic backer. “Traditional transparency film graphics need wider frames to support and hold the graphic in place, whereas printed fabric graphics can be tension fit into very narrow frames. The design of light box frames has changed to accommodate the much larger formats available with fabric graphics.”
Since, as Harvey mentions, light boxes were once intended for rigid material, the install process was less than desirable. The use of fabric changes this. “Rigid materials, such as acrylic, are heavy and difficult to work with. Putting fabric in light boxes has made for easy change out of graphics; ease of handling, folding, and inexpensive shipping; and a higher end and sophisticated appearance,” shares Tara Lamb, president, Global Imaging, Inc.
Lighting advancements influence the architecture of today’s light box frames. Prior to the decrease in the cost of LED lights—which spurred a widespread adoption of this light source—fluorescents were the most popular option for light boxes.
“Fluorescent light boxes are deeper to accommodate the tubes, typically five inches or more in depth. LED technology significantly reduces the size of the lighting source, allowing light boxes to be much narrower in depth, under three inches. LED lighting also allows for the creation of large format light boxes at reduced weights, making installation easier with lower freight costs,” adds Connie Macias, sales manager, DSA Phototech LLC.
Not only are tubular-shaped lights thicker, they can negatively influence the visual impact of the final graphic. According to Blaise Humphries, business unit manager, Decoprint products, DHJ International, over ten years ago, the first generation of light boxes used neon tubular lights. “This often had the drawback of showing horizontal or vertical bars in the image when backlit if the light source was placed too close to the substrate,” he continues.
Frame manufacturers work hard to create extrusion technology that complements a textile’s physical proprieties. Moving away from traditional snap-edge frames, SEG frames are popular.
“Unlike round-beaded finishing options, SEG is a flat silicone welting that can be seated snugly and provide a drum-tight fit. The flat welting is also more secure and easier to tuck into and pull out of the groove, making it easier to change out fabric graphics,” say Tim Bookout, VP – sales, and Gustavo Correa, VP sales and marketing, North America Display Corporation.
As Robb Sarno, national sales manager, Direct LED Frames, marvels, “it is amazing how a simple 3.5-millimeter groove added to the inside of a piece of aluminum extrusion can change the way we look at a light box today.”
Fabric in Light Boxes
When displaying a graphic, printed directly—or transferred—onto fabric, in a light box frame, a number of features influence a PSP’s material decision.
“Of the many print challenges faced by PSPs, few are as quality dependent as illuminated frame system applications,” admits Jeff Sanders, digital fabrics sales, Pacific Coast Fabrics. “Each and every detail in a printed image is accentuated and magnified once lit. It is therefore crucial that a frame system fabric is engineered for color vibrancy, fine line definition, flawless light source distribution, and no fabric pin holes emitting light,” he advises.
Ken Bach, business development director, Aberdeen Fabrics, Inc., says that any type of fabric can be used in a light box—it all depends on what the buyer is looking for. Polyester-based textiles are predominately used. To learn more about specific products designed for light boxes, click here.
Besides fabric type, perhaps the most important consideration is whether to use a woven or a knit. It is an ongoing mystery on how to combine the best features of both a woven and knit fabric.
“Wovens are predominately found in this application with a tight weave and heavier weight characteristics. But then, one sacrifice is not having enough stretch to make finishing easier,” admits Bill Shuford, TexStyles product manager, Beaver Paper & Graphic Media, Inc.
Humphries agrees that a woven textile is dimensionally more stable than a knit. “It offers residual stretch to ensure that when it is correctly mounted in a frame system it is taut like the surface of a drum.”
“Woven fabrics maintain their dimensional stability during the print process. This is important because the graphic must perfectly align with the grooves on the perimeter of the frame. For example, woven fabrics with a consistent shrink rate are preferred because the amount of shrinkage can be more accurately anticipated between fabric lots,” say Bookout and Correa.
The material’s physical properties should offer no pin holing, a smooth surface, and good illumination, recommends Bach, and all three of these properties are attainable with a woven fabric. However, with SEG frames, stretchability is a necessary component.
“Knit fabrics offer a slight elasticity in both directions. This is a lot easier for using fabrics in aluminum frames; this is compared to woven fabrics where usually no elasticity is possible,” explains Hendrik Igler, sales, Georg+Otto Friedrich GmbH.
“A woven isn’t good with stretch, when you pull it diagonally for example it doesn’t provide the desired look. Knit stretches, but it provides too much pin holing, so it won’t provide the same pop as a woven. The ideal mix is a knit/woven, something that can bridge the gap—stretchable, yet durable,” suggests Bach.
The material’s physical properties, the direction a fabric is lit from, and how it is printed also affect choice.
Many components of a fabric need to be looked at, including its weight, color or white point, and stretchability, before deciding if it will excel in a light box frame. Weight, white point, and even stretchability control how the light will be displayed through the fabric, referred to as diffusion.
According to Joe Terramagra, product manager – digital fabrics, Dazian, LLC, the diffusion properties of fabric are a function of the fabric construction, type of fiber, and weight. Fabric color should be the brightest white achievable with the use of optical brighteners. Denier of fiber used in the fabric is a function of fabric construction, which correlates with weight and diffusion properties.
Quality backlit fabric is generally a heavier textile, says Mike Compton, business development manager, Top Value Fabrics. He cites a good backlit as weighing at least 8 oz. on average and premium backlit fabric often weighing at least 9 oz.
“Most authentic backlit fabrics are coated for optimal color density and exceptional print quality. This is important for the elimination of pin holes and hot spots when placed in the frame,” he continues.
Color and a fabric’s white point are key considerations. “The fabric has to hold a lot of ink because when illuminated it should pop—meaning the colors have to be very strong to light up, otherwise it will look washed out,” shares Heather McCusker, wide format specialist, Agfa Graphics.
“The color provides a difference in the final effect of the image, a neutral bright white won’t influence the image,” agrees Igler.
Stretchability should only be considered when popping the fabric into an extrusion, recommends McCusker. “In light boxes you want just a bit of stretch—otherwise it will open up the weave or knit of the fabric, causing pin holes to shine through because of the illumination.”
“With the use of SEG frames, an important consideration is the amount of mechanical give or stretch available from the fabric media. It gives a certain amount of forgiveness in terms of tolerances for finishing and also helps remove minor wrinkling,” says Shuford.
“Another key attribute to a superior light box textile is wrinkle resistance, along with slight stretch for ease in installation, thus preventing sagging caused by too much stretch, once the fabric is in place. Additionally, a quality frame system fabric should be pre-shrunk,” adds Sanders.
Direction of Lighting
Light boxes can be illuminated from the front, behind, or even the side—providing additional benefits that play into the style and feel of the intended message. The direction of the lighting has to be taken into account when choosing the fabric used in the frame.
“If the light source is from behind, widely referred to as backlit, then the PSP would want a fabric that has been engineered for light dispersion so that the light is spread evenly across the surface and there are no hot spots,” adheres Sharon Roland, advertising and PR manager, Fisher Textiles.
Eric Tischer, president, Verseidag seemee US, Inc., explains what to look for when considering frontlit versus backlit, specifically for SEG framing systems. He says frontlit graphics are typically lit from above, so the frames are low profile because no lights are used behind the fabric.
Conversely, backlit SEG frames feature more depth in order to hold the lights, which are lit from behind, although they can be located on the top, bottom, or sides of the frame, adds Tischer.
Printing the Graphic
There are several methods used to print onto fabrics. Direct to print with UV, solvent, or latex is becoming more prominent. The traditional method is dye-sublimation (dye-sub)—direct or transfer.
When it comes to printing onto a fabric for a light box application, sublimation is the process of choice. “No direct print fabric can match the densities achieved through the sublimation process, most notably in areas of deep colors and blacks,” stresses Ronit McGuthrie, product manager – wide format supplies, ACCO Brands.
Between dye-sub processes—direct and transfer, Bach insists direct dye-sub is the best option for backlit graphics. “With backlit, you want to print direct dye-sub because it tends to provide deeper ink penetration. Transfer tends to bleed to one side and then the other.”
Matching Frame and Fabric
The physical architecture of a light box also affects fabric choice. Options include the more traditional snap edge or SEG; in either scenario the fabric must work well with the frame.
“It is important to find a fabric that fits within the bounds of the light box, and allows for the best fit and print vibrancy. Dependent on which type of frame is chosen, the fabric choice may vary based on the available depth of the frame and the style of the application,” explains Jaime Herand, VP of graphic operations, Orbus Exhibit & Display Group.
Tischer points out that the right amount of lighting should be considered. “Depending on the size of the backlit, it is key to have the lighting in the proper locations so that the image pops.”
“Fabrics in shallow light boxes may have hot spots and light bulbs may be visible. Light placement is important for spacing and brightness of the image. Some fabrics require an added layer of material to diffuse the light,” advises Kylie Schleicher, marketing manager, Ultraflex Systems, Inc.
Compton also shares that the “construction and durability of the frame needs to be consistent with the weight of the fabric and the size of the graphic.”
Due to the nature of how the fabric fits into SEG frames—tension fit with silicone beading on the fabric that helps lock it into the frame—PSPs need to account for other considerations that they normally wouldn’t when using a traditional frame.
The fabric needs to be the correct thickness. “It is important that it is thick enough to allow for vibrant color when lit, but thin enough to work with the beading applied to the edges. This ensures that the printed graphics hold vibrancy and quality, while creating a snug fit when inserted into the application channel,” explains Herand.
“The one specific fabric requirement necessary for a SEG frame is that it is designed for strength and ease of use when attaching the keder. A smooth, strong, tear-free surface is a must,” adds Sanders.
Without the proper weight and strength, it is difficult to attach the silicone edge to the fabric. “It can cause headaches such as loose fit, sagging in the middle, and wrinkles where the silicone edge snaps into the frame,” continues Compton.
This is where the right balance of stretch comes into play. “Too small and the fabric becomes overstretched and damaged during install, too large and the fabric sags and the image and lighting suffers,” advises Harvey.
Lamb suggests considering how much or little the fabric will shrink upon sublimation. “This should be taken into account at file preparation. A non-stretch fabric may force straightness, but if its slightly short, it will have no give and the aluminum frame can bow and bend,” she cautions.
The shape of a SEG light box also makes a difference when deciding on the type and construction of fabric used. “When curves or circles are utilized in a frame, the choices narrow. It would be best to utilize a fabric that has built-in stretch in the construction,” recommends Sarno.
Improved ink sets and fabric optimized for digital print influence the framing systems textiles are displayed in. Because of fabric’s ease of use and portability, frame manufacturers enhance extrusion technologies and create SEG frames. Updates in frame size and advancements in lighting are designed to accommodate digitally printed textiles.
With the changes in a frame’s architecture, media manufacturers are creating specific fabrics for use in backlit, frontlit, and edge-lit light boxes. These substrates feature the correct combination of weight, white point, and stretch to perform well in a light box frame.
Jul2015, Digital Output