It may be observed that in the colour mixtures which follow in no case has any white other than white lead and zinc white been used. In actual practice many manufacturers add barytes or some other cheap white to both colours and paints in order to lessen the cost. It is not thought necessary, however, to add these materials in the recipes, it being understood that their use can be proceeded with if necessary. We give a few mixtures for whites which will probably be found useful. There are no particular names applied to the following mixtures.

One part of barytes to six parts of white lead ground in oil makes a good white for outside use.

A permanent white which is not affected by gases, sulphuretted hydrogen, etc., is made by mixing two parts of oxide of zinc with one part of barytes. A warm white is made by mixing a small quantity of oxide of ochre, say one part to one hundred of white lead. Sometimes a little ivory black, say one part to three hundred, is added to the white.

White lead being sometimes a little “off” in colour, that is a little yellow in its cast, some blue is added to counteract this imperfection. Most of the corroders, however, exclude all the lead which is of a yellow cast and sell it to glass manufacturers, for whose purpose it is just as good as pure white.

A very little ultramarine green added to white lead makes a white sometimes called Japan white.

Equal parts of white lead and oxide of zinc are frequently used as a white paint, although two parts of lead to one of zinc gives a better mixture.

Some painters are under the impression that inasmuch as lead and zinc are both derived from metals they will not mix together to form a good paint, there being something of the nature of a galvanic action set up between the two metals. This, however, is an error, for although lead and zinc cannot properly be mixed together by hand yet if they are ground by the ordinary paint manufacturers’ machinery the result is a most durable paint which will last many years; indeed, the writer has found this paint, with proper thinners, one of the best possible mixtures which can be used to resist the destructive action set up by alternate wet and dry days.

White lead is, of course, the staple white and the most important of all painters’ materials. Various new processes in white lead are in more or less successful operation. The old Dutch process, however, must be said to give the greatest satisfaction, generally speaking.

Commercial White.

—Seventeen parts of white lead, three parts of barytes. This is intended to be mixed in oil, not water.

Permanent White.

—The best quality barytes or blanc fixe makes a permanent white when ground in water. In oil it lacks body. For many purposes a white which will last a considerable length of time is made by mixing two parts of zinc white with one part of barytes.

Various Whites Compared.

—Space will not permit of the advantages and disadvantages of the various whites being treated here at length, but the reader can obtain reliable information on the subject from the books of Hurst, Pearce and others, as given elsewhere in this book. Briefly, white lead is valuable because it possesses better “body”—i.e., the property of covering or hiding the surface to which it is applied—than any other pigment. Its poisonous character is against it, as is also the fact that it is affected by certain gases. Zinc is an excellent pigment; it is whiter than white lead, but is somewhat deficient in body. Lithopone and Charlton white are both excellent substitutes for lead, and are non-poisonous.