thermal printer

People don’t think of printers as “cool” gadgets. They’re kinda boring and infamously unreliable. On top of that, they require pricey toner to print anything. Did you know there are printers that don’t need any ink? They’re called “thermal printers.”

You’ve probably seen a thermal printer in your daily life without thinking twice about it. They’re used mostly by businesses, but there are plenty of very affordable thermal printers available online. The technology is pretty cool and could be useful to you.

What Is a Thermal Printer?

There are several different types of printers, but in general, they work by applying liquid ink or powder-based toner to the paper. Thermal printers don’t actually apply anything to the paper. Instead, the paper itself is what makes the image appear.

A typical printer needs to have its ribbon or cartridge replaced when the ink or toner runs out. Since a thermal printer isn’t applying a substance to the paper, only the paper itself needs to be replaced. This makes them easier and cheaper to operate.

Thermal printers are all around us. They’re used to print airline tickets, retail receipts, shipping labels, bank slips, and much more. Many fax machines in the 1990s also used thermal printing technology, but have since been upgraded to laser or inkjet.

Businesses like thermal printers because they are compact, easy to move around, print quickly, and are cleaner and cheaper to operate. If you’ve ever wondered how UPS prints out your shipping label so quickly, that’s thanks to a thermal printer.

How Do Thermal Printers Work?

There are mainly two types of thermal printers: “direct thermal” and “thermal transfer.” We’re specifically talking about direct thermal printers here.

Thermal transfer printers use ink in the form of ribbons (rolls of ink-coated material). The ribbon is heated up in specific spots, which melts the ink-substance onto the paper. Direct thermal printers do not require any form of ink or toner.

thermal printer head
Thermal printer head © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons)

A direct thermal printer is equipped with a “thermal head” that generates heat. This thermal head heats up the special paper in specific spots as it rolls through. Each spot that gets heated up reveals the dye impregnated in the paper.

Since the paper itself is what contains the dye, the quality of the prints can be somewhat limited. Most thermal paper only contains black dye, which is good for printing basic things like recipes and bullet journals. The prints also fade over time, so they’re not great for long-term projects.

HP Sprocket Select
HP Sprocket Select Zink printer HP

One exception is a printing technology called “ZINK,” which stands for Zero INK. Like other direct thermal printers, Zink printers use thermal paper. However, “Zink Paper” has several heat-sensitive layers with cyan, magenta, and yellow dyes embedded.

By precisely controlling the temperature and length of the heat pulses, Zink printers melt the different layers to reveal their colors. A short burst of high heat activates the yellow, a long burst of low heat activates cyan, and now, that “pixel” appears as green. Pretty cool.

Another thing that affects quality is the DPI (dots per inch) of the thermal head. The more “dots” across the head that can be heated up, the higher the resolution will be. A basic thermal printer could have 200 to 300 DPI, while a Zink printer is going to be much higher than that.

Can You Buy a Thermal Printer for Personal Use?

amazon alexa thermal printer
Amazon Sticky Note Printer Amazon

Thermal printers aren’t just for business use. While it’s true that thermal printers are mainly used by businesses, there are plenty of great consumer options. A lot of these printers are for label making, but they can do other cool things, too.

A brand named “Phomemo” has a line of mini thermal printers that can connect to phones and tablets over Bluetooth. They cost anywhere from $50 to $90, depending on the quality you want.

Amazon even has an Alexa-enabled “Sticky Note Printer” that uses yellow adhesive-backed thermal paper. They advertise it as a tool for printing shopping lists, to-do lists, and puzzles.

The aforementioned Zink printers are priced similarly to the Phomemo printers, but the paper is quite a bit more expensive. These are great if you want to print full-color photos straight from your phone.

Are these thermal printers going to replace your inkjet or laser printer? Probably not, but they can serve a useful purpose. The fact that you never have to worry about ink or toner is a huge benefit. As long as you have paper, you can print. Who said printers couldn’t be cool?

RELATED: Stop Buying Inkjet Printers and Buy a Laser Printer Instead

Profile Photo for Joe Fedewa Joe Fedewa
Joe Fedewa is a Staff Writer at How-To Geek. He has been covering consumer technology for over a decade and previously worked as Managing Editor at XDA-Developers. Joe loves all things technology and is also an avid DIYer at heart. He has written thousands of articles, hundreds of tutorials, and dozens of reviews.
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