What is spot UV?

That last point is the one most often missed. Spot UV over a gloss-laminated sheet is gloss on gloss: you have paid for a finishing pass and the result is almost invisible. Spot UV over matte lamination is a genuinely striking effect, and the combination of the two is the single most common premium treatment on business cards, folders and cosmetics cartons.

It is applied as a separate pass from a separate plate, so it needs its own artwork layer — usually solid black shapes marking exactly where the varnish falls. It also has to register to the printed image beneath it, and finishing tolerances are wider than colour-to-colour register on press. A design where the varnish must sit exactly inside a printed outline will show a sliver on one side if the sheet moves; a design where it overlaps deliberately, or covers a whole shape, is much more forgiving.

Raised or textured spot UV lays the varnish thicker so the effect can be felt as well as seen. It costs more and reads as noticeably more expensive.

What to spend it on: a logo, a product name, a single graphic element, a pattern that catches the light as the pack turns. What not to do is varnish large areas or most of the design — the contrast is the whole point, and once everything is glossy there is nothing left for the eye to notice.