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Unfortunately, in some cases it caused noticeable darkening and cracking.It persisted as a pigment until the end of the 19th century. Atramentum (Atramentum Librarium) An old generic type of term referring to the colour of ink - mainly blacks, but also reds, greens, and violets which were the traditional colours used by classical artists and calligraphers.For example: "Ivory black" was produced by burning ivory or bones; "Vine black" was made by charring dried grape vines; "Lamp black" was made from soot collected from oil lamps.Synthetic versions have now replaced these traditional organic forms, except in certain specialized arts, like calligraphy and Oriental painting.Since the late-19th century, the majority of pigments employed by most painters are improved synthetic variants of older colours.
Cadmium pigments were used in both oil painting and watercolour but could not be combined with copper-based pigments. It was a pure form of carbon, and was referred to by a variety of names, depending on how it was made.Superceded by Prussian blue in the early 18th century, and rendered obsolete after the synthesisation of Ultramarine and the development of Cobalt Blue.Barium Yellow A relatively opaque white-yellow pigment, it is a form of Barium Chromate, and is also known as Lemon Yellow.After roasting it was typically mixed with Van Dyke Brown to obtain the richest shades. Burnt Sienna An iron oxide pigment, coloured a warm mid-brown. Cadmium yellow is cadmium sulfide, to which increasing amounts of selenium may be added to extend the colour-range.Viridian is added to Cadmium yellow to produce the bright, pale green pigment cadmium green.