Lakes.—These are made by precipitating colored vegetable tinctures by means of alum and carbonate of potash. The alumina combines with the organic coloring matter and separates it from the solution. The tincture used varies in the different descriptions of lake. The best, made from cochineal or madder, is used for internal work. Drop lake is made by dropping a mixture of Brazil wood through a funnel on to a slab. The drops are dried and mixed into a paste with gum water. It is sometimes called “Brazil wood lake.” Scarlet lake is made from cochineal; so also are Florentine lake, Hamburg lake, Chinese lake, Roman lake, Venetian lake and Carminated lake.

Orange.—Chrome orange is a chromate of lead, brighter than vermillion, but less durable. Orange ochre is a bright yellow ochre burnt to give it warmth of tint; it dries and works well in water or oil, and is very durable. It is known also as Spanish ochre. Orange red is produced by a further oxidation than is required for red lead. It is a brighter and better color.

Greens.—These, of course, may be made by mixing blue and yellow together, but such mixtures are less durable than those produced direct from copper, arsenic, etc. The latter are, however, objectionable for use in distemper or on wall papers, as they are very injurious to health. Brunswick green of the best kind is made by treating copper with sal-ammoniac. Chalk, lead and alum are sometimes added. It has rather a bluish tinge; dries well in oil, is durable, and not poisonous. Common Brunswick green is made by mixing chromate of lead and Prussian blue with sulphate of baryta. It is not as durable as real Brunswick green. Mineral green is made from bi-basic carbonate of copper; it weathers well. Verdigris is acetate of copper. It furnishes a bluish-green color, durable in oil or varnish, but not in water; it dries rapidly, but requires great care in using owing to its poisonous qualities. Green verditer is a carbonate of copper and lime; is not very durable. Prussian green is made by mixing different substances with Prussian blue. There are a number of other greens made from copper, but they all possess in a greater or lesser degree, the same qualities as the foregoing. Emerald or Paris green is made of verdigris mixed with a solution of arsenious acid. It is of a very brilliant color, but is very poisonous; is difficult to grind, and dries badly in oil. It should be purchased ready ground in oil, as in that case the poisonous particles do not fly about, and the difficulty of grinding is avoided. Scheele’s green and Vienna green are also arseniates of copper, and highly poisonous. Chrome green should be made from the oxide of chromium, and is very durable. An inferior chrome green is made, however, by mixing chromate of lead and Prussian blue, as above mentioned, and is called Brunswick green. The chrome should be free from acid or the color will fade; it may be tested by placing it for several days in strong sunlight.

Proportions of Ingredients in Mixed Paint.—The composition of paints should be governed by the nature of the material to be painted. Thus the paints respectively best adapted for painting wood and iron differ considerably. The kind of surface to be covered, i. e., a porous surface requires more oil than one that is impervious. The nature and appearance of the work to be done. Delicate tints require colorless oil; a flatted surface must be painted without oil, which gives gloss to a shining surface. Again, paint used for surfaces intended to be varnished must contain a minimum of oil. The climate and the degree of exposure to which the work will be subjected; thus, for outside work boiled oil is used, because it weathers better than raw oil. Turps is avoided as much as possible, because it evaporates and does not last; if, however, the work is to be exposed to the sun, turps are necessary to prevent the paint from blistering. The skill of the painter also affects the composition; a good workman can lay on even coats with a smaller quantity of oil and turps than a man who is unskilful; extra turps, especially, are often added to save labor. The quality of the materials makes an important difference in the proportions used. Thus more oil and turps will combine with pure than with impure white lead; thick oil must be used in greater quantity than thin oil. When paint is purchased ready ground in oil, a soft paste will require less turps and oil for thinning than a thick paste. Lastly, the different coats of paint vary in their composition; the first coat laid on to new work requires a good deal of oil to soak into the material; on old work the first coat requires turpentine to make it adhere; the intermediate coats contain a proportion of turpentine to make them work smoothly, and to the final coats the coloring materials are added, the remainder of the ingredients being varied as already described, according as the surface is to be glossy or flatted.

The exact proportion of the ingredients best to be used in mixing paints varies according to their quality, the nature of the work required, the climate, and other considerations. The composition of the paint for the different coats also varies considerably. The proportions given in the following table, must, therefore, only be taken as an approximate guide when the materials are of good quality.

Table showing the composition of the different coats of white paint, and the quantities required to cover 100 yards of newly worked pine.

RED LEAD.WHITE LEAD.RAW LINSEED OIL.BOILED LINSEED OIL.TURPENTINE.DRIERS.REMARKS.
Inside work, 4 coats not flatted.
lbs.lbs.pts.lbs.
Priming¹⁄₂166——¹⁄₄Sometimes more red lead is used and less drier.
2d Coat*153¹⁄₂—1¹⁄₂¹⁄₄
3d Coat—132¹⁄₂—1¹⁄₂¹⁄₄*Sometimes just enough red lead is used to give a flesh-colored tint.
4th Coat—132¹⁄₂—1¹⁄₂¹⁄₄
Inside work, 4 coats and flatting.
Priming1¹⁄₂166—¹⁄₂1-8
2d Coat—124—1¹⁄₂1-10
3d Coat—124—01-10
4th Coat—124—01-10
Flatting—90—3¹⁄₂1-10
Outside work, 4 coats not flatted.
Priming218¹⁄₂22—1-8When the finished color is not to be pure white, it is better to have nearly all the oil boiled oil. All boiled oil does not work well. For pure white a larger proportion of raw oil is necessary, because boiled oil is too dark.
2d Coat—1522¹⁄₂1-10
3d Coat—1522¹⁄₂1-10
4th Coat—1532¹⁄₂01-10

For every 100 square yards, besides the materials enumerated in the foregoing, 2¹⁄₂ lbs. of white lead and 5 lbs. of putty will be required for stopping.

The area which a given quantity of paint will cover depends upon the nature of the surface to which it is applied, the proportion of the ingredients and the state of the weather. When the work is required to dry quickly, more turpentine is added to all the coats.

In repainting old work, two coats are generally required, the old painting being considered as priming. Sometimes another coat may be deemed necessary.