Flexography, normally abbreviated to flexo, is a method of printing most commonly used for packaging.

A flexo print is achieved by creating a mirrored master of the required image as a 3D relief in a rubber or polymer material - compare with children's potato printing. A measured amount of ink is deposited upon the surface of the printing plate (or printing cylinder) using an anilox roll. The print surface then rotates, contacting the print material which transfers the ink.

Flexo is so named because it was originally used as a method of printing onto corrugated cardboard which has a very uneven surface. It is required that the printing plate surface maintain contact with the cardboard, which it does by being a flexible. Also unprinted high points on the cardboard must not get printed by ink remnants not on the plate surface, which is achieved by ensuring a sufficient depth for the non-print areas of the plate.

Originally flexo printing was very crude. Over the last few decades great strides have been taken in improvements to the plate material and the method of plate creation - usually photographic exposure followed by chemical etch, but also by direct laser engraving. Full colour picture printing is now possible.

Flexo has an advantage over lithography in that it can use a wider range of inks and is good at printing on a variety of different materials. Typical product printed this way includes: 'brown' cardboard boxes, cornflake packets, crisp packets, yoghurt pot tops, paper serviettes and even wallpaper.

External links

• Flexographic technical association: http://www.flexography.org
• The Norwegian Flexo Forum: http://www.flexoforum.no
• Torda Ink - supplier of flexo inks: http://www.torda.com