What are an ink cartridge’s injectors?

In principle, injectors are the valves or veins that inject ink all over the paper sheet, a process that is done after the print heads get warmed up.

A print heads has may injectors that can become clogged or worn out, eventually burning out and becoming useless.

However, not all injectors burn out at the same time, since this is a progressive process which slowly decreases your printer’s print quality.

Most of the time, this wear shows up on paper sheets as white lines on whatever we’ve printed. The injectors don’t need to be burned out to stop working: they can also become clogged with ink residues, and unclogged when the headprint’s cleaned with special paint thinners.

Leaving the headprint clogged and full of ink will contribute to the injector overheating and burning out, since the ink itself can act as a lubricant and cooling gel for the injector.

This is exactly why we consider headprint cleaning and testing to be essential for optimum injection functioning. This information has been taken from todoinkjet.com

The differences between dyed and pigmented inks

Dyed inks are, by nature, highly sensitive to the type and quality of the paper sheets you print on, since some kinds of paper are made to absorb more ink than others in their fibers and can soak up dyed inks. If the paper isn’t coated and has high fiber content, your prints may have some “spider-shaped” stains just like the ones shown in this picture: when you’re printing in color, what we call a primary diffusion occurs on the upper side of the paper sheet before the ink has had time to dry.

This will produce many different colors from the main three or five ones. If you’re printing with black ink, there should be no ink bleeding at all, as is shown in the next picture.
In order to avoid black ink from “bleeding” into the colored ones, HP decided to replace dyed inks with pigmented ones on their HP600 (29A) line.

Both dyed and pigmented inks are made from a watery base (to to 80% water). The main difference between them lies in the coloring. While it’s completely dissolved in the watery base of dyed inks, pigmented inks have a more solid coloring that cannot be broken up by the water. This dye floats on the base rather that mix itself with it.

Since these dyes are not water-soluble, pigmented inks tend to be more resistant to water, have more defined edges and better overall results when printing colored backgrounds.

Pigmented inks take a bit more time trying than dyed ones, and cannot be used on transparencies.

Another fundamental characteristic that defines dyed inks is that they can be stored in temperatures starting at -10ºC and up to 35ºC. Pigmented inks, however, will not stand temperatures lower than 0ºC. The source article can be found in the following link.