Fast, Quiet, Inexpensive Thermal Printers

Print labels, banners, and badges wirelessly, without ink

High volume printer
Isn't miniaturization grand? Image from January, 1875. Getty & Hulton Archive

Normally, when we talk about printers, we’re talking about machines that transfer consumables, usually ink or toner, to paper. Today, though, we’re talking about a much different type of printer—machines that don’t use ink, toner, or any other type of consumable, such as dye sublimation, foil, or 3-D. We’re talking thermal printers.

The only consumable a thermal printer needs is paper—special “thermosensitive” paper, to be sure, but all you need is paper just the same. While this is convenient, and as you’ll soon see, there are many applications; it also has its drawbacks, making it suitable for only specific types of printing. Even so, as demonstrated in this Lifewire “Leitz Icon Smart Labelling System” article, the breadth of possible applications is extensive.

How Thermal Printers Work

Instead of laying down ink or toner on the paper, thermal printers’ thermal head generate heat, which is then applied to the thermosensitive paper in the pattern to be printed. The treated paper then turns black where the heat was applied. Some thermal printers are two-color (black and another color, usually red). The two different colors are achieved by applying the heat at different temperatures. (Another method, thermal transfer printing, uses heat-sensitive ribbon, instead of heat-sensitive paper.)

A typical thermal printer is a fairly simple device consisting of thermal heads that generate the heat, thereby printing on the paper; a rubber platen, or roller for feeding paper; a spring that applies pressure to the thermal head, thereby applying contact to the thermosensitive paper; and, of course, circuit boards for controlling the device.

The heating elements in the thermal head activate the heat-sensitive coloring layer, which is infused with dye (and other chemicals) that changes the color of the paper. The heating elements are typically comprised of a matrix of small, closely spaced dots, much like a dot-matrix printer. In fact, thermal printers are dot matrix printers, of a sort.

Types of Thermal Printers

Some of the first thermal printers of note were fax machines, and at one point there were millions of them deployed in offices throughout the world. But nowadays the applications for thermal printers are many. After looking at this somewhat short list, if you didn’t already, when you realize what kinds of devices these are, you should realize how many types of thermal printers there really are:

  • Bar code printers
  • Grocery and other retail receipts
  • Gas pump receipts
  • Slot machine vouchers
  • Information kiosks
  • On-demand labels

And, again, that’s only a partial list. Perhaps the two most common applications for thermal printers are receipt and label printers, and the printers themselves run anywhere from about $70 or $80 up to and beyond $2,000—depending on several factors, including speed, volume, and versatility.

Usually these devices are single-function machines capable of doing only one thing—printing one specific type of form or label. And often they are used in busy environments where there’s no time for lengthy media replacement procedures—replace the media cartridge and go.

The End

The more you think about it, the more you realize just how many types of printers there are in the world. Not only do Epson, Brother, and other big printer manufacturers make several types of thermal printers, but so do several smaller companies that make specialty products, such as the abovementioned Leitz Icon label maker.

By popular demand, I’ll be adding a thermal printer section to Lifewire, where we’ll be looking at label and other types of these inkless printers. For some applications, thermal printers are cheaper and easier to use.

(And did I mention? They’re definitely quieter.)