How It Works
Thermography is, as its name suggests, hot printing. It creates raised imagery – and interesting textures – by fusing tiny granules of thermo powder with wet offset inks. The thermography unit is attached to a standard offset press. The thermo powder reservoir releases a shower of granules, dusting each just-printed sheet as it passes beneath. Granules adhere only to the wet ink, and a vacuum immediately sucks excess granules back into the reservoir. The sheets pass directly into the heat tunnel, where the thermo powder melts (at several hundred degrees), fuses with the ink, and is literally baked onto the paper in a matter of seconds et voilà, the ink puffs up and sits proud on top of the sheet.
Inks & Powders
With standard-pigment offset inks, we use clear thermography powder. For printing white, pearlescent or metallic inks, special powders are required. Thermography can look shiny – the bigger the image, the greater the shine. On fine type (such as a response card or menu), the shine is barely noticeable. Thermography feels slightly slick, or waxy, whereas engraving feels slightly chalky.
Why We Love Thermography
It’s quick (because no drying time is required). It’s economical – no dies, less restrictions than other processes. Thermographed dots or icons are a great way to add texture and visual interest to a piece (even a label). Clear thermography on dark stock is cool. We don’t think of thermo as imitation engraving, we think of it as engraving lite.