Inorganic pigments are of mineral origin, some of which include raw umber, ochre, burnt umber and burnt sienna. Artificially prepared mineral colours include cadmium yellow, zinc oxide, etc. Organic pigments are of animal, vegetable or synthetic origin and include indigo, madder, Indian yellow, etc. Synthetic organic pigments such as cerulean blue, cobalt green and cobalt yellow are characterized by great brilliance and intensity and should not be thought of as inferior to their natural counterparts.
Because of the many variable conditions both in nature and in the manufacturing process, many qualities of pigments exist. Most paints are sold in artist and student grade. Artist quality paints contain the best pigments. Student colors generally contain the cheaper pigments, and are coarser in texture. Hue is another way of classifying a paint. Often substitute pigments are used in student grade colors to reduce cost and are hence labeled “hue.” Sometimes the original colors no longer exist, such as with Indian yellow hue, or original pigments are found to be poisonous and are substituted as in the case of Naples yellow hue.
Each type of paint has a different binder that mixes with a pigment to create a smooth consistency. For example, linseed oil is the binder used for oil paint, gum arabic binder for watercolors and acrylic emulsion is the binder for acrylics.