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 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.