Ink might make pretty patterns, but the real beauty is its intricate design

The ink inside your printer is one of the most expensive liquids you can buy. According to previously published Which? research, it can set you back as much as £1.70 per millilitre while a 1985 vintage bottle of Dom Pérignon is a snip at 23p per millilitre.

But those figures can be deceiving. As refined as good champagne is, it doesn’t involve the level of ingredients and engineering that go into creating top quality printer ink. There’s more going on inside your printer cartridge than you might expect.

The seeds of toner: the secrets behind the cartridge

Most black toner is still produced by mixing iron oxide, pigments and polystyrene resin which is then extruded into thin sheets and pulverised into particles using pressurised air. But colour toner now tends to be created in a more unusual way – it’s grown.

The process used to grow toner particles is called emulsification. In the same way that oil and water produce droplets when you mix them, combining a chemical mix with water and heating it results in uniform toner particles whose size and shape can be precisely controlled.

Because the toner particles are extremely similar in size and shape, they move together like a liquid. Around four microns in size, the particles are less than one-tenth of the width of a human hair and that’s after they’ve been given a wax core which acts as a lubricant and prevents the paper from sticking to the printer’s fuser.

Growing the toner around a particle of wax means the printer can operate at much lower temperatures making the process far more energy-efficient. The polymerised toner also emits far less carbon dioxide, nitrous oxide and sulphur oxide than the older process.

Ink obviously has an aesthetic aim, to mark the page, but it also has to be precisely formulated to interact with the mechanism inside your printer and deliver consistent quality page after page. It’s nano-engineered to deliver good prints and a long life for your equipment. Skimp on ink quality and the results could be disastrous.

The colour of money

With inkjet printers, the ink is either dye or pigment based. Dye-based inks use small molecules of colourant suspended in a water-based solution. The mix is squirted from nozzles at high speed and is absorbed into the fibres of the paper.

Because the layer of colour placed onto the page by dye-based inks is composed of single molecules, it lays flat on the surface and reflects light evenly to give vivid tones. The downside is that dye-based inks run if they get wet and can fade quickly (within 10 years, which is considered quick in the printing world).

Pigment-based inks use small balls of plastic suspended in a carrier substance which tends to be water mixed with a solvent. Pigment takes longer to dry than dye-based inks and the particles scatter light, producing less vibrant colours. But pigment is longer lasting than dyes and nano-milling particles to reduce their size has begun to improve brightness.

The colourant in your ink is just one part of a complex mix of chemical components; a selection of additives are included to ensure quality and consistency. Buffering agents control the pH level of the ink, humectants reduce the rate of evaporation and resins increase the resilience of the ink when it’s printed.

Buying third party ink is like buying cheap petrol and replacing the engine every 10,000 miles. It’s a false economy.

Along with that cocktail, fungicides and biocides are added to prevent bacteria from invading the ink and spoiling its effect while surfactants reduce surface tension to ensure a consistent flow of ink through the printer.

Toner, which is used by laserjet printers, is equally as engineered. Made up of positively charged particles combined with solvent, it bonds to the path traced by the printer’s laser to create your printout.

David Sweetnam, European Lab and Research Manager for print technology testing lab BLI International, explains: “It’s essentially great big lumps of carbon ground down until it will fit through a sieve. Creating it is a very advanced process and a lot of toner is effectively grown from seed. Manufacturers keep a very tight control over the particles which reduces wear and tear on components.”

Particles of toner are microscopic and rejected if they exceed a regulation size or are the wrong shape. That ensures they pass like liquid through the printer to be bonded to the paper by the fuser (a heating element).

Why does quality ink matter?

As well as the complex mix of chemicals required to produce good printer ink, the way it interacts with the printer head is key. Katie Waller, senior researcher at consumer magazine Which? says: “There’s a lot of technology in the print head. The number of nozzles can reach the thousands and you’re dealing with millions of droplets of ink.”

This photocopier surfs the web

The old-fashioned photocopier is dead. Here’s the photocopier for the touchscreen age – the Sharp MX3610N. With a 10.1in touchscreen and slide out keyboard, it makes manipulating documents on the fly easy.

The Sharp MX3610N is controlled with the same kind of flicks and swipes you use on your smartphone and the touchscreen panel means you can rotate, reorder and even edit documents to cover up sensitive information on the go.

Best of all, the Sharp MX3610N hooks up to the web using high speed Gigabit Ethernet connection to let you grab documents directly from the web. And if there are documents you regularly need to grab copies of, this photocopier has 86GB of memory to archive them in.

Those droplets need to move through the printing mechanism smoothly without causing clogging. With third-party ink which isn’t precisely calibrated to work with your particular printer, the likelihood of that occurring tends to be far higher.

Sweetnam warns: “The big problem with most 3rd party inks is you’re playing roulette – you don’t know whether you’ll get a good one until you try it and even then you could get a bad batch of a product.”

Third party ink sellers tend to buy their product from whichever supplier is currently offering the best deal. That can often mean you won’t get the same recipe whatever the box claims.

But the effects of buying sub-standard ink can be worse than leaving you with washed out photos or dodgy looking documents, Sweetnam warns:

“It can end up damaging the print head which the manufacturer won’t replace under warranty because you didn’t use their ink. We’ve seen examples where we test a machine and its life expectancy has been halved because of using inconsistent products.”

So while taking a short cut with cheaper ink might look like a good bet, it could end up being a costly move. Sweetnam says: “It’s a bit like buying cheap petrol to put in your car and having to replace the engine every 10,000 miles. It’s a false economy.”

The End
  • Will Ryan

    I’ve always wondered why toner appears to be such a rip off, but now I have a little more understanding. Really interesting article.

  • Aryeh Abramovitz

    Many inkjet printers replace the entire print head every time you buy new ink , so the only thing you are risking by refilling it is a print head you would be tossing anyway.

    • James Holland

      It really depends on the complexity of the printer. Laser printers don’t replace anything when you add in toner, and all sorts of components, like the fuser come into contact with it.

  • 12

    the biggest ingredient is the profit margin :-)