Invisible ink (varnish)
It's a bit of a mystery, that line item on the printer's bill: “Varnish.” What's it about?
Varnish coats and protects printed items. Without varnish, your carefully crafted marketing communication could be smeared with fingerprints. Colors would lack richness. The printed surface would be uneven, and colored areas would get scuffed. Most things that are printed should be varnished.
Varnish shortens turn-around by reducing drying time. Some colors, especially blue, will take a week or more to dry without varnish. Copies wait to dry in stacks with powder between the sheets, but cannot be moved. So while varnish adds to your direct costs, it provides clear benefits in time and quality.
Varnish comes in three major types:
Traditional solvent or water-based varnish, which may be applied to a whole piece or in spots, like an ink
Aqueous coating, which is thicker and dries faster than traditional varnish. It is only used for a whole piece
UV, which is the thickest, most durable - and most expensive - coating. UV may be applied in spots or over a whole piece. It uses include super high-gloss postcards and retail packaging.
In some cases you will need to use a printer with specialized equipment to get the specific type of varnish effect your project requires.
Each type of varnish coating is available in three or more finishes, including high gloss, satin and matte (dull) finish. The varnish is usually selected to complement a paper with a similar finish. This means you can have a high gloss water-based varnish, used on a spot basis, on a high gloss paper. Or perhaps a matte finish aqueous coating on a dull finish paper. Fortunately, you will usually only need to choose between samples of combinations suggested by your graphic designer.
Spot varnish can be used to create drama-high gloss varnish can spotlight specific areas that are printed on a matte background. Varnish may be tinted for subtle design effects. Spot varnish can also be used to avoid undesirable changes in the finish of a paper. By using varnish only over the inked sections of the page, you can achieve many of the benefits while leaving the paper finish unchanged.