This section is from the book "A Treatise On Architecture And Building Construction Vol4: Plumbing And Gas-Fitting, Heating And Ventilation, Painting And Decorating, Estimating And Calculating Quantities", by The Colliery Engineer Co. Also available from Amazon: A Treatise On Architecture And Building Construction.
53. As color descends according to the regular scale from white, and therefore properly terminates with olive, neutral black would here naturally end the series. Practically, however, every colored pigment of any class whatever combines with black. Hence arises a new series in the scale of colored compounds, having black for its basis, distinguished by the term semineutral and divided into three classes, brown, maroon, and gray. Inferior as they are, in point of color, the semineutrals comprehend a great proportion of our permanent pigments, being, so to speak, black tints or shades.
54. Umber is the name of a brown pigment obtained through the agency of oxide of iron from naturally colored clays, some coming from Turkey, and some again from Umbria, in Italy, whence the color takes its appellation. In its natural state it is usually designated as raw umber, while burnt umber, a pigment of darker color than the preceding, is obtained by calcining raw umber at a low temperature.
55. Vandyke brown, hardly less celebrated than the great painter whose name it bears, is a species of bog earth of a fine, deep, semitransparent brown color. The pigment much used and esteemed by Vandyke came, it is said, from Cassel, a town in Prussia. The Vandyke browns in use at present appear to be terrene pigments of a like kind, purified by grinding and washing.
56. Raw sienna appears to be an iron ore, considered as a crude natural yellow lake. Valuable, very absorbent, and firm in substance, it presents, when broken, a glossy surface. It becomes, by burning, a deep orange, more transparent and quicker in drying, and is a valuable color in graining.
57. Sepia is a brown pigment originally obtained from the excrescence of the cuttlefish, sometimes called the inkfish, on account of its affording this dark liquid, used by the ancients both as an ink and pigment. Sepia, though brought originally from the Adriatic, may be obtained from the fish of our own coasts. Of a powerful dusky brown color and fine texture, it works admirably in water, combines cordially with other pigments, and proves very permanent in results. It is mainly used as a water color on account of its reluctance to dry in oils.
58. Asphalt, or mastic, a fireproof and waterproof pigment, is obtained in natural formations, such as the great asphalt lake in Trinidad. Used more as a varnish than a paint, it is, when mixed for use, dissolved with resin in tar oil, in the proportion of about 1/2 pound each of asphalt and resin to 2 pounds of oil, then kept hot till the dissolution is complete.
59. These various pigments may, according to uses and characteristics, be classified:
1. Those more or less transparent and fit for graining and finishing are: all blacks (except mineral blacks), umbers, chrome greens, cadmium yellow, raw and burnt sienna, ocher, French ultramarine, Mars orange, and brown sepia.
2. Those little, if at all, affected by heat or fire-the whites and the ochers, in natural clays.
3. Those for fresco or distemper work are the whites made from sulphate of baryta or carbonate or sulphate of lime, all the ochers, the reds, blues, browns, and blacks.
4. Those more or less injured by damp and impure air, especially sulphureted hydrogen, and are unfit to use in distemper, are white lead, all the yellows, except the ochers, red lead, Chinese and Persian lead, Prussian and cobalt blues, orange salts of lead, and all greens.
5. Those which fade or are affected by strong light -all vegetable colors, including the yellows, Prussian blue, indigo, the peaty browns to a considerable extent, and, in less degree, the madders.