Epson WorkForce Enterprise WF-C21000 ink cartridge, cyan

In colour printing, cyan is one of the three base inks. Mixed with magenta it produces blues and violets, mixed with yellow it produces greens. Skies, water, blue company logos and the cool colours in charts depend heavily on this cartridge. When cyan runs low, greens drift towards yellow and blues towards red, so it pays to replace the cartridge in time.

The supplier's compatibility list contains a single device: the WorkForce Enterprise WF-C21000 D4TW. No other models appear on it, so there is no basis for claiming that the cartridge fits any other printer in the WorkForce Enterprise range. Before replacing it, compare the model name on your printer's label with the name on the list.

Epson itself is listed as the manufacturer, which makes this an original consumable rather than a third-party compatible cartridge. An original cartridge is developed together with the printer it is made for, so the ink and the cartridge design match what the machine expects. In an office that means fewer surprises with colour reproduction and printer messages.

The cartridge comes on its own and contains cyan ink only. Because every colour sits in a separate cartridge, an empty cyan does not force you to throw away magenta or yellow cartridges that are still full. Which colour runs out first depends on what you print: documents with blue logos, maps and charts usually use more cyan than anything else.

It is meant for offices and print rooms that run a WorkForce Enterprise WF-C21000 D4TW and prefer the manufacturer's own consumables. Keeping one spare on the shelf is sensible, so that an empty cyan does not halt a job in progress. The supplier does not publish a page yield, so the most reliable way to track consumption is the ink level shown by the printer itself.