Making Translucent Vinyl Work for You
If you’ve traveled through an airport concourse or shopping mall recently, you’ve probably seen backlit signs pitching everything from home sites to dental services. Take a step outside and you’ll see that these signs are becoming increasingly popular among shop owners for exterior signage as well—providing day and night visibility and visual impact that’s hard to beat.
With recent improvement in wide format inkjet printer and ink technologies, more and more sign shops are finding that they can compete in this lucrative market, providing their customers with cost-effective backlit signs that look great.
The Right Media
Until recently, the vast majority of backlit signs designed for close viewing were produced using transparent film technology and special inks. These prints typically look great and offer extremely high resolution, but they’re also time-consuming and expensive to produce, especially in small quantities.
That’s where translucent PVC films come in. These dense films are formulated to provide even light diffusion and high ink receptivity necessary for producing the saturated images for both daytime—ambient light—and nighttime—backlit—viewing. The satin finish of these films also inhibits external glare and reflections that can detract from the overall effectiveness of the image.
PVC media for solvent inkjet printers provides a range of other advantages for backlit signage as well, including wider film widths—up to 60 inches—to reduce the need for seams, cost effectiveness, and the ability to produce one-off or customized images quickly and efficiently. It also offers the advantage of extended outdoor durability versus traditional backlit film products, including those used in aqueous inkjet printing.
Optimizing Your Prints
Since backlit images have to provide high visibility in both daytime and nighttime conditions, obtaining the right degree of ink saturation is critical on these prints.
Printers often improve translucent film image quality by utilizing the double-pass or multi-pass functionality built into many of today’s inkjet printers and RIP software. While a bit slower, this process can produce images with higher degrees of ink saturation than single-pass printing, resulting in more vivid output.
If you have a heavily saturated graphic image with deep colors, you might want to consider printing two separate images and overlaying one on top of the other. This technique requires careful registration of the images, but when properly done, can produce great results.
You’ll also need to take into consideration the depth of the sign cabinet in relation to the intensity of the backlit light source. While a particular print might work well in a shallow lightbox using a lower-intensity LED light source, the same print might not be ideal in a lightbox with higher-output fluorescent bulbs.
Once you’ve printed your image, you’ll want to protect it with a matching laminating film in a semi-gloss or matte finish. Make sure your inks are fully cured—at least 24 hours—before laminating, to allow the solvent inks to outgas. If your backlit sign will be located outdoors, make sure the laminating film you choose provides additional UV inhibitors to extend the effective outdoor life of your inks.
Images printed on translucent PVC films are typically applied to translucent substrates such as acrylic, polycarbonate, or flexible PVC sign materials, then mounted in stock or custom-built lightboxes. Best results are typically achieved when the translucent media is applied to white translucent substrates. They provide better light diffusion than clear materials—which can often lead to washed out prints or hot spots where the light bulbs show through the printed image.
When it comes to applying PVC vinyl films to large, rigid surfaces such as acrylic or polycarbonate, many installers prefer to use a wet application technique which can be more forgiving, reducing the incidence of bubbles. If your installer uses this technique, however, make sure they squeegee out any moisture trapped between the PVC film and the substrate. Otherwise, you’ll create distracting blotches or raised areas that will reduce the quality of your print.
As with most technical processes, practice makes perfect. With just a little time and determination, you’ll be producing great backlit signs before you know it.