Liquitex Professional Acrylic Ink made with finely ground artist quality pigments instead of colorants. They dry quickly, are permanent, water resistant and non-clogging, which makes them ideal for a variety of techniques from watercolour effects to stamping. Colour Name - Prussian Blue Hue - A deep dark blue transparent color, that recreates the appearance of Prussian blue pigment. Prussian blue was the first known artificially manufactured color and was made by the colormaker Diesbach of Berlin in the early 1700s when experimenting with the oxidation of iron.