Knowing more about the inkjet ink types is an important factor for your successful printer handling and cartridges refilling.
The inks used in the inkjet cartridges are complex chemical solutions with very demanding characteristics. Problem is that these inks have to be very fast drying, because otherwise your fingers could be easily smudge the printout after printing. In the same time however, these inks have to be dry resistant because otherwise they would easily dry out in the cartridge.
Main printer ink types
Although there is a multitude of ink brands, printer inks are basically two types: dye based and pigmented. These two ink types are chemically different and mixing them could eventually be disastrous for your cartridge and even for your printer.
While dye based inks are chemical SOLUTIONS, which means that dyes are being chemically dissolved in a solvent, pigmented inks are SUSPENSIONS. Suspensions are physical mixes where solid particles are being “suspended” in a liquid.
Therefore, for the dye based ink types drying is a reversible process. If a solvent is added to the dried dye based ink, the ink can be dissolved back to its liquid state.
On the contrary, the pigmented ink types drying process is irreversible. As pigmented inks contain tiny solid particles (pigments), once dried these particles form an insoluble compound. Subsequently adding solvents to this compound cannot dissolve it back to its initial liquid state.
This is why pigmented ink types are also called “document inks” – unlike the dye based inks, once dried pigmented inks cannot smear upon contact with liquids or solvents.
Dye based inks
Used mainly in color cartridges, dye-based inks deliver brighter and richer colors, compared to pigmented inks. The small molecular structure of dyes is the reason for the vibrant colors these inks deliver.
However, this tiny molecular structure makes dye based inks soluble even after drying. They can easily smear upon any subsequent contact with water or humidity.
Another drawback of these inks that they are highly susceptible to fading with time. The color vibrancy they deliver doesn’t last long and photos printed with dye based inks tend to fade over time.
Pigmented ink types
As we already said, pigmented inks are physical suspensions and once dried, they form insoluble compounds. Any subsequent contact with water or other solvents cannot dissolve them and smear the printout.
Additionally, because of the insoluble character of the dried ink, pigmented inks are much more UV resistant and do not have the tendency to fade with time. On the other hand, pigmented colors are usually less vibrant and reflective than the dye based ink types.
Another drawback of pigmented inks is that in case these inks dry out in the print head nozzles, it is practically impossible to restore the proper print head operation. A dried print head with pigmented inks usually has to be discarded.