Glossary · Ink

UV printing

UV varnish

A transparent ink laid over the print. It makes areas glossy, protects the colour or creates raised, tactile textures.

Explained in more detail

Clear varnish is printed through its own channel like a colour and set up as its own layer in the software. Applied over the full area, it increases gloss and protects against abrasion. Printed selectively on individual areas (spot varnish), it sets accents, and several layers on top of each other produce tangible relief and texture effects. Whether varnish is possible depends on the machine: some printers have a dedicated channel for it, others share it with a colour. In UV DTF, varnish is often printed as well because it gives the transfer stability; whether it is needed depends on the machine and software.

Where does the term come from?

"Varnish" is the English word for lacquer or varnish. In data sheets, "Gloss" or "Clear" is often also used for the varnish channel; the same pigment-free ink is meant.

In practice

• For gloss, let the lamp cure with a delay so that the varnish flows out; for matt, cure immediately so that the droplets remain as a rough texture.
• In the file, the varnish gets its own spot colour, which must be named exactly as the printing software expects; set the layer to overprint.
• Clear varnish costs about as much as coloured ink, so include it in the unit cost, especially when applied over the full surface of large plates.
• Varnish is more viscous than colour ink and more prone to clogging, so always check the varnish channel in the nozzle check too.
• For heavily handled products such as key rings, plan full-surface protective varnish as standard, as this reduces scratch complaints.

Not to be confused

Varnish does not replace primer: it protects the colour from scratches but does not improve adhesion to the material. If the print adheres poorly, everything flakes off together, varnish included.

Frequently asked questions

Does UV varnish make the print weatherproof?

It protects against abrasion, but does not guarantee UV resistance of the colours outdoors. For outdoor use, ink, adhesion and a test piece in a sunny spot are what count.

Can any UV printer print varnish?

No. Some devices have their own varnish channel, others share it with primer, and some have none at all. This is stated in the datasheet under ink channels.