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 - Transparent Burnt Sienna - A sheer orange brown single pigment color made by burning raw sienna. Sienna is a natural yellow clay found in the earth, which is rich in iron oxide and deepens in color when heated. Named after Siena in Italy, where the pigment was originally sourced, this is a transparent color with red-brown tones.