We tend to take ink`s unparalleled ability to transfer essential information onto a chosen substrate for granted. Even though we can create a huge variety of visible and recognisable images by applying a very thin film of ink and very fine dots, we tend to forget that ink has several unique properties, which must be carefully controlled throughout the printing process (both on contact with the press1 and with the substrate). Moreover, once applied, the ink has to dry – or set – while subsequent prints must be identical (repeatability). To achieve all of the above, ink `uses` just two components: pigments and a vehicle. In a series of two articles, author Karel Schell offers an introduction to the world of ink. Karel Schell holds a physics degree from Delft University. Karel moved to security printer Joh. Enschedé (the Netherlands) in 1977 and joined the board in 1988. In April 1993, he established his own independent techno- logical consultancy, enabling him to share his technological expertise and experience with a diversity of customers in Europe, Canada, the US, Africa and the Far East.