Answer: Thermography!
This is a cost-effective alternative for achieving a raised effect similar to that of engraving, which is why it’s often called “imitation engraving” or “poor man’s engraving.”
Thermography is a heat activated process. A special unit is attached to the offset press and, after the original printing process (while the ink is still wet), the paper is transported through the thermography unit.
Next, the whole sheet is covered with a special thermography powder. While the small granules stick to the wet ink, a vacuum sucks the loose ones up and stores them for re-use. The powder is now fused with heat into a raised, usually glossy, enamel-like look. The actual thermography-treated area has a slick, waxy feel to it. (PaperSpecs PRO members, be sure to check out your complete Guide to Thermography!)