Increasing the aesthetic value of consumer products turned to be pivotal, especially in ceramic manufacturing. Ink-jet printing is a non-impact method based on projecting ink droplets onto a surface. In the drop-on-demand (DOD) printers, ink droplets are ejected, only when required, by the application of an electrical signal on a piezoelectric actuator that squeezes out the droplets.

Many features of ink-jet printing technology make it interesting for decoration of ceramic products. As increasing image resolution is requested, the fact that ink-jet printing involves the smallest droplet volume amongst the decorating technologies allows both a better control of image quality and to get customized products at admissible costs. This is especially true when the quadrichromy process is used, implying four basic colours: cyan, magenta, yellow and black. In fact, the change of the image is simply obtained by changing the software input, without any substitution of mechanical parts, as it happens in the other decoration technologies.