When you think of varnish, you probably think of putting a glossy coat on an old chest of drawers, but varnish is gaining ground in the digital printing arena and you need to know more about it.
Simply stated, varnish is a thin, liquid coating that you apply either before or after you print an image. Varnish allows you to protect and enhance the image quality. It’s clear and can be jetted on top of a printed surface. Just like white ink, you can jet varnish from an integrated print head. You just need the right printer.
But before you rush out to examine new printer options, you need to make sure you are ready to add this to your list of customer options. Specifically, you need to know the types of varnishes, the reasons to varnish, the reasons not to varnish, and, of course, how to varnish. So if you are ready to explore the world of varnish, let’s get right to it.
There are plenty of benefits to varnishing. One of the most obvious is that varnishing can be a smart option for images that customers need to display for the long haul. Since it typically contains Ultraviolet light stabilizers, varnish can reduce fading, yellowing, cracking, peeling, flaking and the like.
Varnishing can also make it easier to clean and handle a digitally printed image. Varnishing can even make a print water resistant, though not necessarily waterproof. So if a digital image is subject to rain or splashing water near a fountain or pool, varnish could be a value-added benefit for your customer. (Just be sure not to over promise varnish’s protection or you could end up with an angry customer who demands a reprint job that comes out of your pocket. Test it for yourself and see the limits of its protection.)
Need more benefits? Here are a few: Varnishing offers a similar look as lamination, but it is typically much less expensive. What’s more, varnish can be printed on certain areas of a print, such as shadows on a ladder, to highlight portions of the page. That’s called spot varnishing and is similar to spot color printing. And varnishing makes the print a little denser, offering a feel of quality.
While the protective benefits of varnishing lend themselves to long-term applications, some of these other benefits make a case for short-term applications as well. Note that not all varnish is glossy.
There are also matte varnishes that merely intend to protect the image from damage without adding the shine. Satin and tinted varnishes are also options. Satin varnish offers sheen while tinted varnish gives the print a bit of color.
How Does It Work?
Old-fashioned varnishing demands a can of varnish and a paintbrush to apply the material to the surface of the print. Some sign shops may still use this practice if they don’t get many orders for varnish or if they can’t afford a printer that does this automatically because printers that offer the option to integrate a separate head for varnish may not be in the budget.
Of course, by far the simplest approach would be to allocate some number of inkjet printheads to the function of “printing” clear ink. The varnish printhead would follow the printing of the colors that form the image to form a topcoat.
“Just like a color, varnish is printed as another ink in areas where one has printed an image. This allows just the image area of the substrate to be protected and enhanced without putting varnish down on the rest of the substrate,” says Xerox digital imaging spokesperson Sandra Mauceli.
For example, she continues, if you have a glass surface and you do not want any varnish on the areas where there is no image, you can print varnish only in the image areas leaving the rest of the glass surface clear.
If you do decide to varnish, experts recommend using coated paper stock for optimal results. And be sure to test out a varnished print before you send 10 or 20 through in mass production to make sure all systems are a go.
Why Not Varnish?
Oh, and before you jump into varnishing with both feet, consider some reasons not to varnish. Here’s one: many varnishes are solvent-based. That means they emit VOCs during the application. That can be hazardous to the operator’s health if they don’t follow the appropriate measures.
Here’s another: though varnishing can protect a print from yellowing, the varnish itself can yellow over time if the liquid contains tung or linseed oil. If you choose to varnish, make sure to choose a material that contains alkyd formulations, but know that this material will not be as glossy or as durable as varnishes with tung or linseed oil. You have to choose your poison, in other words.
Yet another and significant disadvantage is the lack of flexibility in changing the gloss level of the finished graphic, according Maria Bragg, marketing development manager of 3M Commercial Graphics.
“Theoretically, the clear coat inks could be switched or the printer could be engineered to support multiple finishing inks,” she says, “but either of these options potentially effect the cost of the printer and/or reduce manufacturing productivity.”
Choosing the Right Printer
There are plenty of printers that let you print varnish. One of the latest is Raster Printer’s Daytona T600UV. It’s a 60X48-inch flatbed printer that features MEMS printhead technology, hybrid LED/Mercury lamp curing of its UV-curable inks, and a six-color inkset.
The T6000UV uses Raster’s 4000 series UV-curable inks. Users can choose the CMYK+ white and varnish configuration. The option of white and varnish allows users to print onto clear or dark substrates.
Meanwhile, Mimaki’s 5X10-ft UV-curable flatbed printer — the JF-1631 comes equipped with Xaar Toshiba printheads and uses Mimaki UV-curable inks. Its 8-color inks (CMYKcm+W) now include the addition of clear ink in the eighth color slot. The JF-1631 enables overlay printing with white or clear ink. The clear ink acts like a varnish to provide the printed surface with a similar finish.
Durst’s Rho 600, which is similar to the popular Rho 205, offers versatile white-ink printing capability, as well as Durst’s special-effect varnish and spot color options. The platform is designed to be upgradeable. Optional upgrades include higher print speeds, more colors (white and spot), and a Durst exclusive special-effect varnish.
Check with your printer manufacturer of choice to ask about white and clear ink capabilities or paint it on the old-fashioned way. Happy varnishing!
As seen on signindustry.com