Mary Louise McLaughlin (1847 – 1939) in her 1888 book, Painting in Oil, states that the art critic is "interested simply in observing how the painted has mastered the technical details of his work." She, herself, believed that the skill with which the artist applied the paint, "his technique", was more important than the actual colors used; however, she concedes that, no matter the style or technique, the artist must master his materials and not be mastered by them. This would apply to the artist’s paints as well, since, in my opinion, colors with poor properties will ultimately overshadow the best "technique". This article serves as a brief introduction to the colors that would have been commonly found on the palettes of 19th century artists.
A paint is made by grinding a pigment in a liquid vehicle, typically linseed, poppy seed, or walnut oil, to form a dispersion. The pigment particles are not dissolved, but merely dispersed throughout the liquid. The best paints were made from pigments that had long-lasting color (permanence), not affected by exposure to light or atmosphere (darkening or fading), and not deleterious to the desired color when compounding.
Pigments can be classified as either inorganic (mineral), organic (lakes and madders) or synthetic. Inorganic pigments are the "native earth colors" and calcined native earths (clays) containing iron or manganese. Lake pigments are made by precipitating an organic dye onto an inert base (alumina hydrate, barium sulfate, clay, chalk, gypsum). With the exception of madder (dye from the root of the Rubia tinctorum) lake, lake colors are non-permanent pigments, replaced in the late 1860s by synthetic versions. Synthetic inorganic pigments are made by chemical processing from raw inorganic products (iron oxides, lead, sulphide, chromium, cadmium). Newer synthetic pigments have been produced since the turn of the 20th century; however, the following pigments are ones that would have been commonly found on the palettes of 19th century artists.
White pigments: Flake white, composed of lead carbonate or zinc white, composed of zinc oxide.
Black pigments: Lamp black (carbon black), a light, fluffy pure carbon pigment made by burning oils and collecting the soot produced; ivory black (blue black), an impure light-weight carbon made originally by burning ivory, later made from charring bones.
Yellow Pigments: Yellow ochre, an opaque pigment made from bright-yellow natural clay, colored by hydrous iron oxide; Naples yellow a pale yellow pigment made by calcining (drying at a high temperature) lead and antimony oxides; Raw sienna a brownish yellow earth color from natural clay containing iron and manganese; Italian ochre made from natural clay; Aureolin/cobalt yellow (synthetic, made from cobalt potassium nitrate); Lemon yellow (synthetic, made from natural barium chromate); Lemon, Pale, Deep Cadmium yellows (synthetic cadmium sulphides and zinc sulphides); Mars yellow (synthetic ferric (iron) hydroxide);
Red pigments: Vermillion (originally from the toxic mineral cinnabar, later from mercuric sulphide); Light red, a bright scarlet pigment made from the iron oxides in steel mill slags; Indian red, a deep brick red pigment with a bluish undertone composed of iron oxide made from steel mill slags; Venetian red, a native earth pigment; Rose Madder (Madder lake); Mars red (ferric oxide); red ochre made from red clay or by calcining yellow ochre.
Brown pigments: "earth colors" or "mineral pigments" are made from natural clay containing the metals iron and manganese. The browns are raw umber (cool greenish-brown); burnt umber (dark reddish brown pigment made by calcining raw umber); raw sienna (brownish-yellow); burnt sienna, an opaque red-brown permanent pigment made by calcining raw umber; Mars brown ( medium chocolate color); Van dyke brown (earth color containing peat); Caledonian brown (a native earth, similar in color, but inferior to burnt sienna);
Blue pigments: Genuine Ultramarine blue (brilliant blue with purple undertone, y produced from the natural semi-precious stone lapis lazuli.); Artificial (French) ultramarine (produced heating clay, soda ash or sodium sulphate, coal, silica, and sulfur.); Cobalt blue (clear bright blue, made by combining cobalt and aluminum oxides with phosphoric acid with a greenish undertone); Cerulean blue (a bright, deep sky blue made by roasting cobalt and tin or chromium oxides); Prussian blue (ferric ferrocyanide, a deep cyan-blue pigment with a greenish undertone).
Green pigments: Veronese green, also known as viridian and permanent green (light & dark), hydrated chromium hydroxide, with an emerald green under tone.
Orange pigments: Cadmium orange (cadmium sulphide); Burnt sienna (calcined raw sienna); chrome orange (lead chromate); Mars orange (lead chromate).
Violet pigments: purple was not often included on the artist’s palette as it could easily be made from rose madder and a blue.
Other vehicles may be added either by the artist who mixed his own paints or by the manufacturers of tubed. Beeswax or aluminum stearate (stabilizers) to keep the pigment suspended in the oil, or a siccative (drying and preserving agent) or turpentine (paint thinner) are often used to modify the properties of the paints to obtain the particular effect the artist wants to convey.
A parting note--as Marion Kemble states in his book, Lessons in Oil Painting (1888), "the shortest road to good coloring is through a simple palette" and that artists should "exert our ingenuity in an endeavor to discard those [colors] we can do without.