Spot UV is an additional coating of clear gloss that is applied to specific areas on your print (as defined in your press-ready file setup).
It is a specialty finish that adds an extra touch and eye-catching, but classy, dimension to prints. It can be applied to a small area or cover a large portion of artwork. Commonly, designers will apply the Spot UV on their logo or as an overlaid clear pattern.
See: Spot UV product page for a gallery of photographs of this coating.