The DANIEL SMITH Indigo formula mixes Indanthrone Blue with Lamp Black for an extremely lightfast, intense dark that closely matches true Indigo. Transparent, yet high in tinting strength. Use Indigo wherever dusty purples are desired, it evokes a feeling of atmospheric depth used for expressive, moody skies. Try flowing short strokes of Indigo into water, add touches of Sepia and Quinacridone Burnt Orange to create branches and birch trees. Historically Indigo, used since the early Egyptian times, has been a very important blue dye in fabrics as well as art materials, though not lightfast like DANIEL SMITH’s Indigo Watercolour. Natural Indigo is a deep blue colourant named anil, obtained from the sprigs of the indigofera plant.