Daler-Rowney FW Pearlescent Inks are water-based acrylic colours producing a shimmering pearl effect. Pigments are large in particle size so will not go through fine line nozzles for airbrushes, nor will they be suitable for technical pens or fountain pens. The best means of applying pearlescent colours is by using a dipper pen, ruling pen or brush. These acrylic-based inks are water-soluble when wet, but dry to a water-resistant film on most surfaces. All colours are very to extremely lightfast.