The properties of the finished print are determined to a large degree by the chemical make-up or 'functionality' of the ink. These properties include all of the end use requirements such as color, adhesion and resistance properties together with any specific properties that may be needed for the end application. In addition, the chemistry of the ink plays a major part in the way that the image is formed.
Many of these properties come into play a fraction of a second after the inkjet droplet has landed on the substrate. During this time, the droplet has to wet the surface by a predetermined amount so that the image is formed correctly, and has to start the process of bonding with the surface. A short time later, the ink needs to dry if it is a water based ink, or cure if it is a UV system. It is during this process that the properties such as chemical and physical resistances are formed. The lightfastness is determined partly by the selection of the pigment, and partly by the balance of the ink system, so these properties are incorporated into the design specification for the ink. Pigments have to be dispersed into the ink, and dispersion science is a key Fujifilm technology.
All of the components in the ink have to be tuned to each other as the overall performance requires everything to work together.