Creating a Selective Shine in Digital Wide-Format Artwork

Images printed with different levels of gloss are quite impactful. It gives a designer the power to point the viewer’s eyes to very specific areas within the artwork. At times, creating certain areas of gloss in a design is used as an artwork element — for example, when gloss letters are added to a solid color background as a very subtle effect. But, for brand owners, it offers the control to focus on the product, headline, price, and other important communication elements.

Printing with inkjet printers — particularly using aqueous or UV inks — has historically delivered one type of finish, typically satin. If you wanted to offer a glossy finish to the artwork, it meant going offline and adding a layer of varnish. Gloss varnish was added to the entire image or sometimes it was added to those certain areas that the customer wished to ‘pop’ out of the image. Or, at times, the digital printer had to be stopped and reset to print the gloss areas.

After experimenting with inkjet printers and certain inks, there’s an easier way to create spot gloss images. It turns out that the curing times of some UV inks deliver different effects. In fact, if you are willing to wait a little longer on the inkjet printer — just a few seconds for the curing process — a gloss finish can be delivered rather than satin. The print shop that can offer gloss has a distinct advantage over its competitors, because a gloss finish is often a preferred effect.

The Process

Attempting spot gloss manually is very tedious and prone to error. It requires the prepress department to create two separate ‘images’ — one of the satin areas and one of the gloss areas. Then, the press operator RIPs and prints the two ‘images’, carefully changing the digital printer’s gloss/satin settings between the two print passes. Often, an entire run is printed in satin, and then all the half-printed substrates are returned to the printer for the gloss layer — a great way to invite misregistration.

Recent changes in the RIP and printer software make the process much simpler. With the right equipment, producing a print job with spot gloss on a UV inkjet digital printer is very similar to producing a regular print job, with just a couple of additional prepress steps. The first requires someone to edit the artwork and produce separate ‘masks’ of the printed image areas, defining which should be gloss and which should be satin — in much the same way as would be done to create the varnish plate. While the designer who originally creates the artwork might prefer to define the gloss ‘layer’, many printing companies prefer to provide the service themselves as they have more experience working with the tolerances of the process.

The second step is to combine the varnish layer with the satin layer in the artwork file, so that the combined satin and gloss image is processed in the same way as a standard image — i.e., sent to a RIP, processed, and printed using the correct machine settings. The RIP and the printer both understand which areas are gloss and which are satin — and print them accordingly, automatically using the correct UV ink curing settings.

The development of this process moves it from a manual procedure to one that is much more automated and seamless than before. Originally the two images would have been RIPped separately to the printer, and printed consecutively. The operator would be required to make the requisite changes to the UV and other printer settings between layers, with a greater opportunity for errors to creep in.

It is worth noting that because the image is combined, there is no danger of losing registration between the two images. The inkjet printer does not stop for a second image to be loaded, where there might be a chance of the substrate moving, the file being loaded into the wrong position or an incorrect file loaded.

In addition, the level of gloss in the gloss area of the image can be varied from a matte to full gloss. This additional level of control allows the designer to consider the end user’s application. Areas of high gloss can be difficult to see when viewed at certain angles or under certain lighting conditions, so POP displays might look better in a matte finish, still giving the requisite ‘pop’ to the image. Or, with a lower level of gloss, a display can benefit from the slight sheen, while still retaining ample visibility. This process is already receiving high marks in the field.

Innomark: Taking Spot Gloss to New, and Different, Levels

Innomark Communications creates custom merchandising retail solutions that define brands. They are recognized across the country as one of the best and fastest growing providers of temporary and permanent Point-Of-Purchase displays and other types of visual merchandising materials. A good deal of their success is their ‘can-do’ approach to work. If it can be done, they can do it —often exceeding expectations. Because they are specialists in all print methods — litho, web, digital and screen — they can select which print process, or combination of processes, will best suit any given project.

The company has been operating an Inca Onset S20 for a couple of years. Most of their work consists of in-store posters and POP, although an occasional packaging assignment is not uncommon. “While we already owned an Inca Turbo inkjet printer, we needed more capacity and liked the print quality and the speed of the Onset S20”, explains Mark Long, Innomark Director of Prepress and Digital Printing. “We also print a lot on static clings, foils, steel and other unusual materials. The ability to print CMYK with white on a faster machine was particularly intriguing.”

When they acquired the Inca Onset S20, Innomark quickly showed their customers samples of the gloss effect they were able to create. It was very different from that of other digital inkjet printers — similar to a litho quality print, according to Long. Once customers saw the samples, they were all interested because the artwork pops out much more than they thought possible.

It is pretty clever the way Innomark sets up spot gloss and satin. They use both Adobe Illustrator and Photoshop to prepare the artwork. “We separate the satin and gloss portions from within the art file. It takes some experience, but we’re pretty comfortable with it,” explains Long. “We’ve made some cool patterns — for example, a leather pattern as a background or wallpaper that really pops out. For Express Clothing Stores, we have printed a solid black satin background with a glossy black lion on top of the satin. We had some work for Nike where the background was printed in satin, while the shoes popped out in gloss.”

Innomark works with the various levels of gloss that are available, and have learned that they do not have to apply the maximum gloss to attain a very attractive and powerful effect. “Of course, we also need to be careful about store lighting. We temper down the gloss effect to a level that is not unreadable due to lighting glare,” says Long.

Because Innomark has a number of print process options, consistency is also important. On their litho presses, Innomark typically uses aqueous inks on glossy coated stock. For their shorter runs they use the gloss option on the Inca Onset S20 to match the litho sheets.

However, their bread and butter is unusual art effects. “We have printed a lot of display materials directly on foil for Victoria's Secret. We’ll print different patterns in gloss — heart shapes on top of a solid white background. It’s a strong gloss and flat effect.”

Innomark continues to experiment. “We’ve been blending artwork rather than showing a direct, hard contrast between gloss and satin. We mix gloss and satin effects in the image so that there is a smoother transition. For example, we worked on a background where there was graffiti — skull and crossbones — on a brick wall. Certain shadows and some of the detail of the image were gloss and the rest were satin. We worked carefully with the image so that there wasn’t a hard edge,” remembers Long. “We also worked with artwork where flames that were part of the graphics were printed in gloss and melded into the background so that satin and gloss lines were hard to find.”

While the spot gloss print process on the digital printer is about 20 percent slower, the bottom line is that it’s still nicer and faster to use than an offline varnish layer. “The effect is pretty simple to achieve with the Inca Onset S20,” concludes Long. “And the customers love it.”