Glossary · Ink
White ink
Opaque white ink that is printed beneath the coloured inks. Without it, prints on dark or transparent materials would be pale or barely visible.
Explained in more detail
White ink usually contains titanium dioxide as a pigment. It is heavy and settles in the tank, the tubes and the print head, which is why many machines have circulation or a stirrer for the white ink. If you do not use the printer for a longer time, you should move the ink regularly and run nozzle checks. White serves as a white underprint, as an opaque backing layer in reverse glass printing and as a base for relief. At the same time it is the ink that clogs nozzles most often.
Where does the term come from?
The term is a direct description of the colour. In device specifications you often find only the abbreviation W, for example in CMYKW for cyan, magenta, yellow, black and white.
In practice
- With many manufacturers, white ink is more expensive than colour and is usually printed over the full area, so it is often the biggest ink cost.
- On machines without circulation, shake the white ink as specified by the manufacturer; Mimaki recommends at least once a week during breaks.
- Before the actual print, print a small white area on waste material until the white covers evenly.
- Print the nozzle check for white on dark material or on transparent film in front of a dark background, as it is invisible on white paper.
- For leather, film or canvas, some devices offer a flexible white ink that does not crack when bent.
Frequently asked questions
Why does white ink clog so often?
The pigment titanium dioxide is heavy and settles in the cartridge, tubing and print head. Without regular agitation, a thick sediment forms that clogs the nozzles.
Do you always need white ink?
No. On a white or very light background, colour alone is enough, and on natural wood or brushed metal it can be intended to let the material show through.