Is Clear a Colour? If Only the Mona Lisa Could Talk

Though you can’t see glaze clearly, it has enhanced some of the most iconic images in the world – then and now.

A secret ingredient behind Mona Lisa’s mysterious smile is hidden in plain sight. French research suggests that Leonardo da Vinci used up to 40 layers of clear glaze—that he possibly smeared on with his fingers—to create Mona Lisa’s signature characteristic.

Other Old Master painters, including Michelangelo (on the Sistine Chapel ceiling), Rembrandt, and Sandro Botticelli, also used glaze to add dimension and drama to their works.

Even if you’re not one of the Great Masters, clear can still take an image to the next level, bringing depth and intensity not possible without it. “Light travels inside the painting’s surface. Then the light is coloured by the glaze as it returns to the eye. Applying many glazes make paintings look darker because so much light is trapped inside the paint film,” colour maker Robert Gamblin said during a lecture at the Portland Art Museum.

This image by Xerox uses clear dry ink to make the taxis stand out.

In digital printing, clear dry ink can be used to brighten another colour. “We use it like a hit of gloss on top of a particular area to emphasise it,” says Yat-Ming Wong, a senior design and development engineer at Xerox. “If you have a print that is mostly CMYK and then you hit a spot with clear dry ink, that will draw your eye to it.”

Minuteman Press in North Palm Beach, Florida used 14 layers of clear to create these business cards for HEAL Behavioral Health.

And it doesn’t have to be just artwork. One client in Florida wanted business cards that stood out, so we ran clear dry ink 14 times over small dots that got larger and larger, giving the paper the feeling of pebbles.

Intrigued by the effects of clear – even if it isn’t a colour? Don't possess the skills (or multi-year timeframe) of da Vinci? Xerox can help make your prints pop.

This article is part of Xerox’s Colour Campaign series that tells stories about the world’s most intriguing visuals and images. By investing in CMYK Plus Technology, we have the tools and the experts to help you add the effects of clear dry ink to your next project. Find out more here.