Raised printing conjures images of high-quality workmanship and the finest stationery. You can achieve the effect with various machines.
Thermography is the process that creates raised print. With raised printing, you can actually feel the ink on the paper, and the ink has a shiny appearance. Historically, this effect could only be achieved by the very expensive method of engraved printing. Thermography is known as “imitation engraving.”
Raised print is created in the thermographic process by adding a powder to wet ink and heating it. The powder creates a puffed appearance when heated.
For small applications, a table-top machine will suffice. Powder is applied by hand, and the excess is shaken off. The sheet is then placed in a heat tunnel to create the raised print effect. Table-top machines are labor intensive.
In large operations, thermographic machines are fully automated and work in conjunction with printing presses. Sheets are pulled from the press and under the powder unit. A vacuum removes the excess powder, and the sheet moves via conveyor through the heat tunnel and then through a cooling unit.
Various powders can be used to achieve different effects. Some include glitter, pearlescent, metallic and laser-safe. The latter is important if letterhead is to be later imprinted via laser printer; laser-safe powder will not re-melt under the heat from the printer.