10 fascinating facts about laser printers you probably didn't know

It might be sitting in the corner of the office, printing and copying hundreds of documents for your business - but there's a lot more to laser printers than you might expect.

Now, we love testing and reviewing printers of all types at TechRadar Pro - "Where would we be without them?" we ask ourselves. And laser printers are especially interesting (seriously!). From deploying technologies that emerged from the 60s, components that operate at skin-searing temperatures and ink that isn’t actually ink, there’s a surprising amount going on inside these unassuming machines.

Don’t believe us? Just read on and discover ten incredible facts about laser printers – and you might look twice at your office device next time you need to print a report.

1. Laser printers were invented in 1969

It’s no surprise that laser printers have lots of history – after all, they’ve had time to become small, affordable and ubiquitous – but did you know that laser printers have actually been around since the 1960s?

The first laser printer prototype was developed by an engineer called Gary Starkweather, who worked in the product development department at Xerox.

Xerox dominated the photocopier market at the time, but he had the idea to use a laser beam to transplant a new design to the copier’s drum, and the laser printer was born. He moved to the Xerox Palo Alto Research Center in 1971, continued working on prototypes, and by 1976 the first commercial devices were being used in data centers.

2. There's more history than you might think

By 1982, laser printers were being produced commercially for home and office use, and Apple were rumored to be involved – because Steve Jobs spotted the Canon LBP-CX while buying floppy discs for the upcoming Apple Macintosh computer.

Another print pioneer, John Warnock, founded Adobe and was persuaded to license some of his technology to Apple for a new Apple-branded printer.

Consequently, the Apple LaserWriter printer was announced in 1985. Its support for the PostScript and AppleTalk technology, created by Adobe and Warnock, helped drive down costs for the new Apple printer – and ensured that it worked well with those new Apple Macintosh computers, Adobe’s software and new design tools like Aldus PageMaker.

The result? A revolutionized desktop publishing industry that transformed the landscape of books, magazines and brochures – and a legacy of publishing using Adobe and Apple software that still dominates.

Don’t forget Gary Starkweather in all of this, either. The original inventor of the laser printer worked at Apple in the 1990s where he invented color management technology.

He even consulted on the digital effects for Star Wars: A New Hope in 1977, and won a technical Academy Award in 1994 for his work with Lucasfilm and Pixar.

3. The first commercial laser printer was produced for 23 years

That first high-speed commercial model, the IBM 3800, replaced the archaic line printers that used to attach to mainframe computers in data centers.

The 3800 churned out an impressive 215 pages per minute at a relatively modest resolution of 240 dots per inch, and could produce 45,000 characters per second – six times faster than the fastest printer available previously.

Amazingly, IBM refined and updated the 3800 with faster, crisper output, smaller designs, and innovations like long-life components until it was discontinued in 1999 after more than 10,000 IBM 3800s had been deployed globally.

4. The first HP LaserJet was outrageously expensive

The original HP LaserJet arrived in 1984 and was the first laser printer designed for mass-market, office use.

Given the price of printers today you’d be forgiven for thinking that the original LaserJet was just as accessible, but that’s not necessarily the case – it printed eight pages per minute, it used an 8MHz Motorola processor, and cost a mighty $3,495. That’s the equivalent of $10,968 in today’s money.

5. Laser printers operate at nearly 400°F

Laser printers seem mundane, but inside they’ve got some components that get so hot that they could cause third-degree burns.

A key component of every laser printer is the fuser unit, which fuses the toner powder and paper together to actually create prints.

To get the job done, toner needs to be melted so it can fuse with the paper – which means that the fuser needs to operate at temperatures approaching 400°F. That’s as hot as an oven and hot enough to deliver a serious burn to anyone unlucky enough to touch that sort of temperature, and it means that the ink doesn’t ever smudge or run. It also means that the paper has to move seriously quickly through the printer to avoid burning.

Ever wondered why laser printers produce documents that feel warm? Now you know.

6. The ink? It’s not ink

If you hear someone mention the toner used in laser printers then you’d be forgiven for thinking about ink, but it’s actually nothing of the sort.

Toner is actually a dry powder that’s made from fine plastic particles, usually made from polyester resin. They’re combined with pigments and other additives to produce the colors required.

Because laser printing works by heating the toner up until it melts and fusing the melted particles with paper, ink would simply not function properly.

There are advantages to using toner, though: because it’s melted and bonded to paper, it doesn’t smudge immediately after printing in the same way as conventional ink – a factor that supports the faster printing typically found in laser devices. Toner is more resistant to fading than conventional ink, too.

7. Toner has some surprising ingredients

When laser printers first emerged, there wasn’t much attention paid to the safety and environmental credentials of toner. So, back then, you’d regularly find soot and rust if you delved into the mixture – and iron oxide to make it magnetic.

And while things have improved since the 1970s, there’s still a broad array of substances inside your average toner cartridge.

The vast majority of toner is made from plastic that’s milled to a superfine grain – the smaller that gets, the better the print quality.

Plastic doesn’t conduct electricity, so those particles can hold charge. That’s crucial when you consider that laser printers function by manipulating toner using positive and negative electrical charges on the various drums inside.

Most toner these days is made from polyester, but there are several other substances at play. Polypropylene wax is used to stop toner getting stuck to things, and a high-quality type of soot called Carbon Black is often used to create the deep black tones that a good laser printer should produce.

Elsewhere, expect different pigments depending on the color of the cartridge, tiny glass beads to improve the flow of toner over paper, and chemicals to further control electric charges.

8. Lab-grown toner

Traditionally, toner is made by combining all of the relevant ingredients into a single block of material – and then grinding it down until it reaches the required size and shape. It’s then put into cartridges and can get to work in laser printers across the globe.

These days, though, users are demanding more detail and better print quality from their laser printers. To deliver that, manufacturers need to produce smaller particles with more consistent milling quality. Tto get that level of quality, some companies are now using chemical processes to grow toner particles in labs and factories.

The result? Smaller, more consistent shapes, which means more detail, more accurate colors, and more efficient toner.

9. Laser printers use lenses and mirrors, too

As the name suggests, laser printers use laser beams. When you want to print, a laser turns on and off at high speed to target particular sections of a photoreceptor drum.

The drum is positively charged, but those laser hits neutralize sections of the drum with a negative charge – essentially “painting” the design on the drum in negatively charged spaces.

The laser works with a movable mirror and a selection of lenses to render the design on the drum. This means that the laser doesn’t have to move, which reduces the risk of malfunctions and means repairs are easier.

10. Laser printing is based on Xerography

Xerography is a dry copying technique invented by American physicist Chester Carlson in 1942.

It works by creating an electrostatic image on a photoconductive surface, such as the drums found inside modern laser printers. These electrostatic images attract toner particles, allowing them to be transferred to paper and fused to the material.

The history of Xerography can be traced even further back to the dry electrostatic printing process invented by Georg Christoph Lichtenberg in 1778.

After patenting his invention, Carlson started to develop his process into a commercial product in 1946 – and a firm called the Haloid Photographic Company saw potential and signed an agreement to support that development.

It took nearly twenty years until an automatic Xerography process was developed, but that resulted in the first commercial copier being launched and the Haloid Photographic Company changing its name to Xerox.

Fast forward to 1969, when Gary Starkweather saw printing potential in copiers that relied on the older Xerographic technique – and you can trace a line all the way to the present day, where you’ll find laser printers in virtually every office.

For our top picks see our guides to the best home printers and best laser printers.