There are many variations of ink on the market today, but when it comes down to it, there are really only two different types of ink out there: dye ink and pigment ink. They both have their own properties, strengths and weaknesses. Like most things in life you are often trading off one advantage for another. So what are the differences.

Pigment ink is essentially a waterproof ink that is made to "stick" permanently to paper and run very little, it is sometimes used by tattoo artists, (India ink is a popular type of pigment ink and is one of the oldest kinds of ink in the world). The clear advantage of pigment ink is its water resistance, but as mentioned pigment inks have some downsides. Firstly, pigment inks are more difficult to print and write with because they don't dissolve completely in water, a symptom of their water resistance property. Pigment inks are also very expensive and don't offer the same brightness and colour depth as other types of ink.

Dye ink is the other main type of ink (used in fountain pens and gel pens). Dye ink has been around for about as long as pigment ink, but there are some differences and benefits in its properties. Firstly it is not as permanent as pigment ink, dye ink is easily smeared when wet and it has a higher propensity to fade over time. Dye ink is however generally cheaper than pigment ink it also produces brighter more vibrant colours.

So that’s the differences between the two main types of ink now lets take a look at what that ink has to do. Aside from leaving a mark on some paper or other material, the ink may have to remain unchanged in its cartridge for two years or more. Then when it is used it must withstand the heat and pressure of being shot through a microscopic hole in a print head after being heated suddenly to around 300 degrees C. The ink must then travel the equivalent of a stone falling 200 metres, (and here’s the big ask) hit the paper and not bounce or splash, it must dry instantly and not fade for decades. We obviously demand a lot from our ink these days!

Knowing all of this it’s not surprising that it takes from three to five years to develop one new ink formulation and then there are many thousands of tests it must undergo before it can be made available to buy. Tests for durability and usage, and then tested in all the different printer types, it’s no small feat. It takes teams of highly skilled chemical engineers and process engineers to complete the development of a new ink formula. So next time you print something remember all the science that has gone into performing that simple task.