VERDIGRIS

Verdigris is mentioned in Greek and roman literature, using the word aeruca to denote various blue-green and green corrosion products formed at the surface of copper, copper alloys and copper ores. Pliny for example mentioned that aeruca can be scraped from natural copper ore. Theophilus described a viride hispanicum and a viride salsum, the latter formed when copper covered with honey and slat is exposed to the vapors of urine or acetic acid. Its manufacture creates many acetates of copper, each differing in color, solubility and general behavior, all being verdigris. Pliny mentions that verdigris was often used as a pigment in antiquity, and though copper was found in numerous green and grayish green paint samples of paintings from Rome and Pompeii it was not established whether they contained verdigris or malachite. It was used to an enormous extent in the middle ages, made through formation on copper; by burying copper sheets in fermenting marc; grinding copper filings with vinegar, and so on. If there was lead in the copper, some white lead may have been produced along with the verdigris. If bronze or brass was used instead, no doubt the product was somewhat different as well. The apple vinegar used in England would have also altered the product bringing into it organic salts (this was a passing vogue however).

In the fifteenth century, the milky juice of Euphorbia, a spurge, was used most likely to make the soluble green a little waterproof. There is a modern copper salt that we call verdigris, but we cannot assume that the medieval verdigris was the same thing. With all the different preparations, we find variations in its solubility (sometimes it was completely insoluble in water), and its stability, having spread into parchment and stained, corroded or eaten it away so that the painted parts actually drop out of the page; other times it has stayed in place over time and kept its transparent blue-green color without distress. In medieval recipes, to make the color richer, sap green was sometimes mixed in it. In all periods, to make it warmer and more grass green, saffron was blended in, which over time generally faded out or has been lost in the darkening of the verdigris, with the exception of especially well preserved manuscripts. In early Italian, Netherlandish and German paintings, is was widely used to produce the green tones for landscapes and drapery, because neither mixtures of blue and yellow pigments nor malachite and green earth possessed as strong a color. It was common to glaze over an opaque body color of lead white combined with verdigris, or verdigris with lead tin yellow, with a copper resinate layer to produce a deep saturated green.

By the eighteenth and nineteenth centuries, it was rarely found. Emerald green and viridian were available as early as the nineteenth century: hardly surpassable in brightness, but verdigris as an oil medium in tube color was available in France by the LeFranc brand as late as 1928. It does not last except under favorable conditions. It is susceptible to the action of prolonged moisture, readily blackened by alkalis (often used in cleaning pictures), reacts unfavorably with other pigments often aiding in their deterioration as well, and may be darkened by gases in the atmosphere. As hinted at earlier, it is also terribly destructive to paper. Much of the darkened verdigris areas in medieval and Renaissance painting is constantly misleading to art historians. As a note: verdigris was the cause of the blackening of the shadows in the canvases of later masters such as Rubens, who used it in oil instead of tempera and without protective varnishes. As popular and beautiful it may have been in the fifteenth century to Italian painters, the damages and discolorations have left us with little evidence of the colors their writings rave about. Time effects no other color so badly, and tempera samples are mostly what has survived, though they too are badly stained with brown marks. There is reason to believe however, that these changes in color occurred rather slowly through time, having remained green for two to three hundred years before the damage took effect. Another great difficulty with using verdigris was its incompatibility with white lead and orpiment. It was therefore desirable for the painter to have substitute greens and yellows, to avoid the inconvenience of having to replace his white lead with bone white or another inert substitute. Alternatives to verdigris and orpiment began to make their appearance a bit before the fourteenth century, and during the century they developed rapidly.

By the fifteenth century, there was no reason for painters, easel or manuscript, to use either of these two incompatible colors, unless if by choice. Leonardo DaVinci: "To make a fine green take green and mix it with bitumen (asphaltum) and you will make the shadows darker. Then for lighter green with yellow ochre, and for still lighter green with yellow, and for the highlights pure yellow; then mix green and turmeric together and glaze everything with it. Verdigris with aloes, or gall or turmeric makes a fine green and so it does with saffron or burnt orpiment; but I doubt whether in a short time they will not turn black. Ultramarine blue and glass yellow mixed together make a beautiful green for fresco, that is wall-painting. Lac and verdigris make a good shadow for blue in oil painting. Grind verdigris many times colored with lemon juice and keep it away from yellow."

VERMILION AND CINNABAR

Vermilion: This is now the standard name given to red artists' pigment based on artificially made mercuric sulfide (mercury and sulphur). The common red crystalline form of mercuric sulfide is called cinnabar, a name reserved only for the natural mineral. The natural product found chiefly in Almaden and Idria has been eliminated for practical purposes (including that it is slightly poisonous). The properties of both natural and artificially prepared are practically identical. Cinnabar, a dense red mineral, is the principal ore of mercury or quicksilver. It is widely found but not abundant, and from theophrastus we discover that cinnabar was known in Greece as early as the sixth century BC and perhaps Asia Minor long before that. It was not however, used in Dynastic Egypt or Mesopotamia. The best cinnabar came from Spain, but there were deposits of it in Italy at Monte Amiata, not far from Siena, and elsewhere in Europe (A version known as Monte Amiata, from that area is available in very small quantities from Kremer fine art, on Elizabeth Street in New York).

There are deposits of Cinnabar which would not make good pigment, but which can be used as a source of Mercury. We don't know when scientists first discovered how to make mercury from cinnabar by depriving it of its sulphur content; but we do know that this was understood in the third century A.D. as described in the writings of the alchemist Zosimus. Mercury was a source of great interest to medieval alchemists as its appearance and chemical behavior were the basis of a very large part of alchemical theory and practice. They were regarded as the parents of all metals, and the marrying of mercury to sulphur, the manufacture of vermilion, the re-synthesis of these elements into the likeness of cinnabar from which the mercury was extracted, was a consummation greatly admired and devoutly practiced. To do so it is necessary to mix mercury with sulphur and heat them together; if simply mixed and ground together, a black sulfide of mercury is formed, but at the proper temperature this vaporizes and recondenses in the top of the flask in which it is heated. The flask is then broken and the vermilion is removed and ground. Upon grinding the red color begins to appear, and the longer it is ground, the finer the color becomes.

This evidence first appeared in the eighth century A.D.. We are not sure if the invention of vermilion was known in Hellenistic times, or whether it was a product of Syrian or Arabic alchemy, or Byzantine or European, but we've safely assumed that the knowledge of it was popularized in Europe under the influence of Moorish science after the twelfth century. Although the late eighth century recipes prove that the making of vermilion was understood before the year 800. However, vermilion (and in early reports we use this term loosely as it is possible that in terminology it may have still been called cinnabar, even though the process of extraction was reversed), is not generally considered today to be a permanent pigment. It has been known since roman times, and that specimens of vermilion darken when exposed to light. (In the 1920s samples were observed to withstand exposure to sunlight for at least ten years. In other tests it has been discovered that impurities in the alkali polysylfides used to "digest" the pigment, led to the instability of the red. This catalyzes the transition of the red to black). Also, we've found that the darkening of vermilion occurs mainly in paintings in egg tempera but it is not unknown in oil paintings.

As the ancients knew this there were attempts to counteract its natural darkening; i.e. the vermilion wallpaintings in Pompeii were covered in wax as an attempt to preserve them. Naturally this greatly altered their appearance. It is however fairly unreactive to other colors' chemical makeups, therefore when mixed with lead white to produce flesh tones (as was common) it did not produce the black sulfides. The traditional use of red glazes of madder, kermes, and cochineal lakes over vermilion underpaint not only increases the purity of the color but has been shown to reduce the tendency to darken as well. It is also known that the farther light can penetrate into the binding medium., the more quickly the vermilion will darken, thus again the use of varnishes and glazes to protect the color. Because of its cost and the poor lightfastness of some varieties, vermilion has long been substituted and sophisticated with the addition of red lead, chrome orange and organic colorants. Carmine vermilion was often a mixture of red iron oxide and vermilion. Under the name American Vermilion, chrome orange pigment and mixtures of red lead and lakes have been sold, toned or dyed with a permanent red called Para red, and jfor lighter shades with Lithol or Toluidine. Before the discovery of the permanent Aniline Reds, American Vermillion was sold under the name of VanDyke Red, and was composed of a very deep lead chromate. Little is known of the composition of these reds, but when composed of lead and a permanent dye, it is permanent to light, but not to gases.

Antimony vermilion was introduced in England in 1847, but never gained widespread use. The lakes alone, based on monolite red, lithol reds, eosin and other synthetic dyes of appropriate hue were once called vermilionettes. Two such reds, one based on Toluidine red and the other a mixture of eosin and naphthol struck on barytes have been found on early Chinese ceramic objects. From the 1950s, a range of dark red to bright orange colors, based on mixed crystalline compounds of mercuric sulfide and cadmium sulfide were introduced by an American Manufacturer as Meracadmium pigments. To give vermilion an agreeable luster in manuscript decoration, the use of egg yolk along with the glair was how the color was normally tempered in books. In tempera painting on panel,, vermilion was tempered with egg yolk alone, or whole egg. In the fourteenth and fifteenth centuries, in the northern countries of England, France and Germany, they would add warmth to the color by adding saffron. In fourteenth century England, a decoction of walnut bark was sometimes used to enrich the color. In Italy and France only, illuminators used to blend it with Minium to make it brighter and warmer, especially if the vermilion which had been tempered and washed repeatedly had become dingy in the process. End result is that there are too many questions about the stability of vermilion to use it in any traditional sense, thus the enormous number of other reds available on the market today. This however should not prevent someone from capitalizing on its instabilities for their own purposes.

Following are several quotations about the pigments which should be of interest: Leonardo Da Vinci, 1493: To make a fine red take cinnabar or red chalk or burnt ochre for the dark shadows and for the lighter ones red chalk and vermilion and for the lights pure vermilion and then glaze with fine lake. Church, 1890: Vermilion was formerly known as vermiculus, cinnabaris, cenobrium, and minium; the last name is now appropriated to red lead. Vermilion and vermiculus are derived from the Latin vermes, a name originally designating the kermes insect found in the ilex or evergreen oak and used for the preparation of a red dye. From kermes, in its turn, the words crimson and carmine are derived. The name cinnabar is supposed to be of Indian origin, and was sometimes used to designate Dragon's blood, a red resin. Theophrastus informs us that two kinds of cinnabar were known to the Greeks. One of these was undoubtedly real cinnabar (chiefly from Spain), the other was red lead. Pliny's cinnabar or Minium was true vermilion; so was the Minium of Vitruvius. Theophilus called it Cenobrium. Harley, 1982: In English two names, cinnabar and vermilion, have been used interchangeably in the past to describe either the natural or the manufactured product, but by the seventeenth century, vermilion was used more frequently.

Pliny, 77A.D.: Almost the entire roman supply of cinnabar came from Sisapu (Sisopo) in Spain. (A reference most likely to the famous mines of Almaden, which are still the most important source of Mercury in the world). "Nothing is more carefully guarded. It is forbidden to break up or refine the cinnabar on the spot. They send it to Rome in its natural condition, under seal, to the extent of some ten thousand pounds a year. The sales price is fixed by law to keep it from becoming impossibly expensive, and the price fixed is seventy sisterces a pound". (This is supposedly a colossal price, and therefore it must have been of a very high quality.): Brelich, 1904: Cinnabar was mined at the turn of this century in the province of Kweichow, and produced quicksilver from it in Iron and clay retorts. It was exported to different parts of China "Where it is used for the manufacture of vermilion, for which there is great demand throughout the Chinese empire." Vitruvius, 1st century A.D.: "When the lumps of ore are dry, they are crushed in iron mortars and repeatedly washed and heated until impurities are gone and the colors come." He refers to the use of cinnabar in coloring the polished stucco finish of interior walls where it is only stable if not exposed to the sun. Cennino, 1400: By the fifteenth century, almost everyone who had any interest in making vermilion knew how to do it. "If you want to take the trouble, you will find plenty of receipts for it, and especially by asking of the friars. But I advise you rather to get some of that which you find at the druggists' for your money, so as not to lose time in the many variations of procedure." Eugene Fromentin 1876: "None of Ruben's tones is very rare in itself. If you take a red - his red - you can easily dictate its prescription; it is vermilion and ochre - not very finely crushed, and used just as they are after the first mixing."

VERTE ANTIQUE

Artificial Malachite.

VICTORIA GREEN

A bright color tone made from light permanent green and zinc yellow, but also often from cheap, much adulterated pigments like Paris blue and zinc yellow. There is much confusion about this color.

VINE BLACK

Charcoal made from young shoots of grape vines were referred to in medieval times as the best of blacks. It is now referred to as more of a blue-black, considering the coolness of the grays that it produces in mixtures. It was important that the vine sprigs be thoroughly burnt and reduced to carbon, otherwise the color was brownish and an unpleasant consistency; but they must not be burnt in the air or they might reduce to ashes instead of to carbon. So they had to be packed tightly in little bundles in casseroles, covered and sealed, and baked in a slow oven. The resulting charcoal was used in sticks for drawing; or for painting it was first powdered and ground up dry, and then mixed with water and ground for a long time between two hard stones.

VIOLET CARMINE

Same as Purple Madder, with a fair amount of permanence.