Lead white
Composition and Properties of Lead White
Lead white is basic lead carbonate 2 PbCO3·Pb(OH)2. It is soluble in dilute acids as are all carbonates. Traces of hydrogen sulfide gas in the atmosphere react with lead white and result in black lead sulfide. In spite of these facts lead white has been preserved over centuries in oil paintings.It is a fast-drying white pigment when used in oil because of its catalytic effect on the hardening of oils and it is not affected by light. Lead white should not be compatible with sulfide pigments such as vermilion (mercuric sulfide), but no dramatic examples of blackening of mixtures of these two pigments have been observed.
Names
Berlin white, Cremnitz white, Cremser white, ceruse, flake white, Dutch white, Vienna whitePW 1, CI 77597Old English lead “lead, leaden vessel,” from West Germanic *lauda– (source also of Old Frisian lad, Middle Dutch loot, Dutch lood “lead,” German Lot “weight, plummet”), a word of uncertain origin. From Online Etymology Dictionary
Preparation
Attention: lead white is highly toxic and should not be used by anyone not trained to handle it.Lead white can be prepared in numerous ways. One of the possible processes can be described as follows:Strips of metallic lead are placed in porous earthenware pots, over weak acetic acid (vinegar) in sheds with fermenting manure that produce heat and CO2. After a few months, the acetic and carbonic acid react with the surface lead forming a white crust that is scraped off, dried, and ground.The mineral hydrocerussite is of the same chemical composition but it was never employed as a pigment for oil painting.
History of Use
Lead white has been in use since antiquity and it was the most important white pigment until the end of the nineteenth century. It was used for grounds, for lightening other pigments, for the depiction of light and also in its own right as a white pigment. The pigment was replaced by less toxic white pigments such as zinc white and titanium white in the twentieth century.It was first mentioned by Theophrast in fourth century B.C. in his “De Lapidibus” (1)“… Besides these [other colored stones], white lead also is produced artificialy. A piece of lead as big as a brick is placed above some vinegar in a cask. When after about ten days the lead has acquired thickness, the cask is opened and a kind of mildew scraped from the lead, which [the lead] is repeatedly placed in this way until it is used up. The scrapings are pounded in a mortar and continually strained away; and the white lead is the matter finally left deposited.”The following graph gives the frequency of its use in the paintings of the Schack Collection in the Bavarian State Art Collections in Munich (2).Examples of use
