Evidence of date.These paper-marks in some cases afford useful evidence as to the origin and date of a manuscript or printed book; but too much reliance should not be placed on such evidence, since paper often remained for a long time in stock, and the productions of one manufactory were frequently exported for use by the scribes and printers of more than one distant country^[247].

Paper of Oriental make has no water-mark, but the earliest linen-paper of the fourteenth century made in Christian Europe always has a water-mark of some kind, very clearly visible.

Earliest cotton paper.The dates of paper manufacture. The earliest paper appears to have been made in China at a date even before the Christian Era. Its manufacture was next extended in Syria, and especially to Damascus^[248]. This early paper was made of the cotton-plant, the "tree-wool" of Herodotus. Hence it was called charta bombycina or Damascena, or, from its silky texture, charta serica. Paper of this class, almost as beautiful in texture as vellum, is still made in the East and used for the fine illuminated manuscripts of India, Persia and other Moslem countries.

Arab MSS. on paper.Many Arab manuscripts written on cotton-paper of as early a date as the ninth century still exist. The Moslem conquerors of Spain and Sicily introduced the manufacture of this charta bombycina into western Europe, and to some small extent it was used for Greek and Latin manuscripts during the tenth and eleventh centuries. It was, however, rarely used in Christian Europe till the thirteenth century.

Wool-paper.At first cotton only was used in the manufacture of paper, but gradually a mixture first of wool and then of flax or linen was introduced.

Peter, who was Abbot of Cluny from 1122 to 1150, in his treatise Adversus Judaeos mentions manuscripts written on wool-paper, made "ex rasuris veterum pannorum."

Linen paper.In the fourteenth century linen-paper began to be made; at first mixed with wool, and then of pure linen. This fourteenth century paper is distinguishable by its stoutness, its close texture, and its thick wire-marks; the water-mark being especially clear and transparent. Paper was frequently used for official documents, charters and the like before it came into use for manuscript books^[249].

Early MS. on paper.The British Museum possesses one of the oldest known books on paper (Arundel Manuscripts, 268); this is a collection of Astronomical treatises written by an Italian scribe early in the thirteenth century.

In the fourteenth century the Spanish manufactories of cotton-paper were on the decline, and the first manufactory of linen-paper was started at Fabriano in northern Italy. In 1340 another manufactory was set up in Padua, and before the close of the fourteenth century paper was made in nearly all the chief cities of northern Italy, especially in Milan and Venice, and as far south as Florence and Siena.

In Germany paper-making began in Mentz in about 1320; and in 1390 a manufactory was started at Nuremberg with the aid of Italian workmen. South Germany, however, was supplied with paper from northern Italy till the fifteenth century.

In Paris and other places in France paper began to be made soon after the first manufactories in Italy were started.

Paper in England.In England cotton-paper, especially for legal documents, was largely used in the fourteenth century. In Oxford, in the year 1355, a quire of paper, small folio size, cost five pence, equal in modern value to eight or nine shillings. In the fifteenth century its value had decreased to three pence or four pence the quire.

Paper does not appear to have been made in England till the reign of Henry VII.; before that time it was mainly imported from Germany and the Netherlands.

Earliest English paper.All Caxton's books are printed on foreign paper, and the first book printed on paper which was made in England was Wynkyn de Worde's Bartholomaeus, De proprietatibus rerum, printed about the year 1495, four years after Caxton's death, with the following interesting colophon, which alludes to the first paper manufactory in England, set up by John Tate at Hertford.

This colophon, which does not do credit to Wynkyn de Worde's literary style, runs thus:

During the fifteenth century the making of paper reached its highest degree of perfection, and in the following century its excellence began to decline.

Beauty of Venetian paper.The Venetian paper of about 1470, used, for example, in the printed books of Nicolas Jenson and other printers in Venice, is a substance of very great beauty and durability, inferior only in appearance to the very best sort of vellum. It is very strong, of a fine creamy tint, and sized^[250] with great skill, so as to have a beautiful glossy texture. For the illuminator's purpose it appears to have been almost as good as vellum. It even receives the raised mordant for burnished gold of the highest beauty and brilliance.

The very small quantity of good paper that is now manufactured, mainly for artistic purposes, is made by hand in exactly the same way that was employed in the fourteenth or fifteenth century.

Most paper is now made by machinery, and as a rule contains more esparto grass than pure linen fibre.

The Metals and Pigments used in Illuminated Manuscripts^[251].

Fluid and leaf gold.Gold and silver or tin. The splendour of illuminated manuscripts of almost all classes, except manuscripts of the Irish school such as the Book of Kells, is largely due to the very skilful use of gold and silver. These metals were applied by the illuminator in two ways, first, as a fluid pigment, and secondly in the form of leaf.

The fluid method appears to have been the older. It is easier to apply, but is not comparable in splendour of effect to the highly burnished leaf gold, which was used with such perfection of skill by the illuminators of the fourteenth century.

Method of grinding.Fluid gold was made by laboriously grinding the pure metal on a porphyry slab into the finest possible powder. This powdered gold, mixed with water and a little size, was applied with a brush like any other pigment; see Theophilus, I. 30 to 33^[252]. When dry, it could be to some extent polished by burnishing, but as it was laid directly on to the comparatively uneven and yielding surface of the vellum it never received a very high polish. As a rule therefore fluid gold was left unburnished, and its surface remained dull or mat in appearance.

Dull and burnished gold.For this reason it was not unfrequently used in conjunction with burnished leaf gold, a fine decorative effect being produced by the contrast of the mat and polished surfaces. Thus, for example, in fourteenth and fifteenth century manuscripts a delicate diaper of scroll pattern is sometimes painted with a fine brush over a ground of burnished gold leaf.

In the fifteenth century, during the decadence of the illuminator's art, the use of fluid gold, which had previously greatly diminished, was much revived, especially for the background of the realistic borders in Flemish manuscripts^[253], for touching in the high lights of miniatures, and for many other purposes. When used to cover large surfaces, it is always unsatisfactory in effect and has little decorative value.

Cistercian severity.The preparation of this gold pigment was a very slow and laborious matter. The severe Cistercian rule regarded this process as a waste of precious time; and indeed the use of gold in any form was prohibited in the manuscripts used in Cistercian Abbeys. In the dialogue between a Cistercian and a Cluniac monk, De diversis utriusque ordinis observantiis (Thesaur. Nov. Anecdot. Vol. V. 1623), the Cistercian asks "what use there can be in grinding gold and painting large capitals with it"; aurum molere et cum illo molito magnas capitales pingere litteras, quid est nisi inutile et otiosum opus? St Bernard himself had an even stronger objection, not only to gold in manuscripts, but to any ornaments with grotesque dragons and monsters, on the ground that they did not tend to edification.

Fluid silver.Fluid silver was prepared and applied in the same way, but it was much less used than gold pigment. A very beautiful effect is produced in some of the gorgeous Carolingian manuscripts by using in the same ornament both gold and silver, which mutually enhance each other's effect by contrast of colour.

Leaf gold.Burnished Gold leaf. The extraordinary splendour of effect produced by skilfully applied gold leaf depends mainly on the fact that it was laid, not directly on to the vellum, but on to a thick bed of a hard enamel-like substance, which gradually set (as it got dry) and formed a ground nearly as hard and smooth as glass; this enabled the gold leaf laid upon it to be burnished to the highest possible polish, till in fact the gold gave a reflexion like that of a mirror. This Mordant ground.enamel-like ground, or mordant as it was called, was commonly as thick as stout cardboard, and its edges were rounded off, which has the double result of making the gold leaf laid upon it look not like a thin leaf, but like a thick plate of gold^[254], and at the same time the rounded edges catch the light and so greatly increase the decorative splendour of the metal.

Convex surface.Thus, for example, the little bosses and studs of gold, which are strewn so thickly among the foliage in the illuminated borders of Italian manuscripts of the fourteenth and fifteenth centuries, are convex in shape, like an old-fashioned watch-glass, and each boss reflects a brilliant speck of light whatever the direction may be in which the light falls upon the page. Perhaps the most sumptuous use of gold leaf is to be seen in some of the early fourteenth century French manuscripts, in which large miniatures are painted with an unbroken background of solid-looking burnished gold, with a mirror-like power of reflexion.

It was only by slow degrees that the illuminators reached the perfect technical skill of the fourteenth century in their application of gold leaf.

Purity of the gold.In the first place the purest gold had to be beaten out, not the alloy of gold, silver and copper which now is used for making the gold leaf of what is called "the finest quality." The English illuminators at the close of the thirteenth and in the fourteenth century frequently got their gold in the form of the beautiful florins of Florence, Lucca^[255] or Pisa, which were struck of absolutely pure gold^[256]. In England there was no gold coinage till the series of nobles was begun by Edward III.^[257], but these were of quite pure gold, like the Italian florins, and so answered the purpose of the illuminator.

Another important point was that the gold leaf was not beaten to one twentieth part of the extreme tenuity of the modern leaf. The leaves were very small, about three by four inches at the most, and not more than from fifty to a hundred of these were made out of the gold ducat of Italy, which weighed nearly as much as a modern sovereign^[258].

In many cases, we find, the illuminator prepared his own gold leaf, and it was not uncommon for the crafts of the goldsmith and the illuminator to be practised by the same man. For example the Fitz-Othos, mentioned at page 112 as a distinguished Anglo-Norman family of artists in the thirteenth century, were skilful both as makers of gold shrines and as illuminators of manuscripts. Many interesting notes about the Fitz-Othos and other artists employed at Westminster during the thirteenth and fourteenth centuries are to be found among the royal accounts now preserved in the Record Office: see Vetusta Monumenta, Vol. VI., p. 1 seq.

Among the accounts of the expenses of decorating with painting the royal chapel of Saint Stephen at Westminster in Edward III.'s reign, we find that John Lightgrave paid for six hundred leaves of gold at the rate of five shillings the hundred, equal to about £5 or £6 in modern value. And John "Tynbeter" received six shillings for six dozen leaves of tin used instead of silver, not because it was cheap, but because tin was not so liable to tarnish.

These accounts are in Latin, which is not always of Ciceronian purity; a classical purist might perhaps carp at such phrases as these,

Item. Pro reparatione brushorum, viij^d, under the date 1307; and, in the following year,

Item. Unum scarletum blanketum, ij^s vij^d.

The scarlet blanket was not bought to keep the artist warm, but to make a red pigment from, as is described below at page 246.

Goldsmith artists.This close connection between the arts of the goldsmith and the illuminator had its parallel in other branches of the arts, and with results of very considerable importance. Many of the chief painters and sculptors of Italy, during the period of highest artistic development, were also skilful goldsmiths, as for example Ghiberti, Verrocchio, Ant. Pollaiuolo, Francesco Francia and many others.

This habit of manipulating the precious metals gave neatness and precision of touch to the painter, and in the art of illuminating manuscripts taught the artist to use his gold so as to produce the richest and most decorative effect.

The gold mordant.The mordant. We now come to the most difficult part of the illuminator's art, that of producing a ground for his gold leaf of the highest hardness and smoothness of surface. It is a subject dealt with at much length by all the chief writers on the technique of the illuminator, from Theophilus in the eleventh century, down to Cennino Cennini at the beginning of the fourteenth^[259].

Though differing in details, the general principle of the process is much the same in all; the finest possible sort of gesso, plaster, gypsum or whitening, was very finely ground to an impalpable powder, and then worked up with albumen or size to the consistency of cream, so that it could be applied with a brush. After the first coat was dry, a second and a third coat were added to bring up the mordant to the requisite thickness of body, so that it stood out in visible relief upon the surface of the vellum.

In order that the illuminator might see clearly where his brush was going, and keep his mordant accurately within the required outline, it was usual to add some colouring matter, such as bole Armeniac (red ochre), to the white gesso, which otherwise would not have shown out very clearly on the cream-white vellum. In many cases, however, this colouring matter is omitted.

Application of leaf.When the last coat of the gesso-mordant was dry and hard, its surface was carefully polished with the burnisher and it was then ready to receive the gold leaf; several days' waiting would often be required before the whole body of the mordant had set perfectly hard. White of egg was then lightly brushed over the whole of the raised mordant, and while the albumen was still moist and sticky, the illuminator gently slid on to it the piece of gold leaf, which he had previously cut approximately to the required shape. He then softly dabbed the gold leaf with a pad or bunch of wool, till it had completely adhered to the sticky mordant, working it with special care so as completely to cover the rounded edges. After the albumen was quite dry, and the gold leaf firmly fixed in its place, the artist brushed away with a stiff brush all the superfluous gold leaf; all the leaf, that is, under which there was no mordant-ground to hold it fast.

Burnishing process.The gold was then ready to be polished. For this purpose various forms of burnisher were used, the best being a hard highly polished rounded pencil of crystal or stone, such as haematite, agate, chalcedony and the like; or in lack of those, the highly enamelled tooth of a dog, cat, rat or other carnivorous animal was nearly as good^[260]. In fact patience and labour were the chief requisites; one receipt, in Jehan le Begue's manuscript, § 192^[261], directs the illuminator to burnish and to go on burnishing till the sweat runs down his forehead. But caution, as well as labour, was required; it was very easy to scratch holes in the gold leaf, so that the mordant showed through, unless great care was used in the rubbing. In that case the illuminator had to apply another piece of leaf to cover up the scratches, and do his burnishing over again. To secure the highest polish, illuminators burnished the hard mordant as described above before laying on the gold leaf. In most cases two layers of gold leaf were applied, and sometimes even more, in order to insure a perfect and unbroken surface.

Application of gold.All writers speak of this burnishing as being a very difficult and uncertain process even to a skilled hand, requiring exactly the right temperature and amount of moisture in the air, or else it was liable to go wrong. If the gold was to be applied in minute or intricate patterns the illuminator did not attempt to cut his leaf to fit the mordant-ground, but laid it in little patches so as to cover a portion of the ornament. The superfluous gold between the lines of the pattern was then brushed away, as the leaf only remained where it was held by the mordant. With all possible care and skill, it was hardly possible always to ensure a sharp clean outline to each patch of gold; and so one commonly finds that the illuminator has added a black outline round the edge of each patch of gold, in order to conceal any little raggedness of the edge.

Receipts for the mordant.As examples of mediaeval receipts for making the mordant I may mention the following:—

"Mix gypsum, white marble, and egg-shells finely powdered and coloured with red ochre or terra verde; to be mixed with white of egg and applied in thin coats, and to be burnished before the application of the gold." When dry, this mixture slowly set into a beautiful, hard and yet not brittle substance, capable of receiving a polish like that of marble, and forming the best possible ground to receive the gold leaf. Much of its excellence depended on the patience of the illuminator in applying it in very thin coats; each of which was allowed to dry completely before the next was laid on. When ready to receive the gold leaf, after the burnishing of the mordant was finished, some purified white of egg was brushed over to make the gold leaf adhere firmly so as not to work loose or tear under the friction of the burnisher.

Receipts for the mordant.In some cases white lead (ceruse) was added to the gesso, as, for example, in a receipt, given by Cennino Cennini (§ 131 to 139, and 157,) for a mordant made of fine gypsum, ceruse and sugar of Candia, that is ordinary pure white sugar^[262]. This is to be ground up with white of egg, applied in thin coats and burnished. To colour the mordant Cennino adds bole Armeniac, or terra verde, or verdigris green.

Giovanni da Modena, a Bolognese illuminator, gives the following receipt for a different gold-mordant to be used with oil instead of albumen or size^[263]. Instead of gesso it is to be made of a mixture of white and red lead, red ochre, bole Armeniac and verdigris; the whole is to be ground first with water, then thoroughly dried, and again ground up with a mixture of linseed oil and amber or mastic varnish.

This variety of mordant appears to have been used in a good many fifteenth century Italian manuscripts. It is not such a good mixture as the gesso and white of egg, as the oil used to mix with it is liable to stain the vellum through to the other side of the page, and even to print off a mark on the opposite page, especially when the book has been severely pressed by the binder.

Tooled patterns.Tooled patterns on gold leaf. In many Italian and French manuscripts, especially of the fourteenth and fifteenth centuries, a very rich and brilliant effect is produced with tooled lines impressed into the surface of the flat gold. Diapered and scroll-work backgrounds, the nimbi of Saints, the orphreys and apparels on vestments, and many other kinds of decoration were skilfully executed with a pointed bone or ivory tool, impressed upon the gold leaf after it was burnished, and through the gold into the slightly elastic body of the gesso-mordant. Stamped patterns.Patterns were also produced by the help of minute punches, which stamped dots or circles; these, when grouped together, formed little rosettes or powderings, like those used in the panel paintings of the same time. Gold treated in this way had to be of considerable thickness, and in some cases, when a large flat surface of mordant was to be gilt, as many as three layers of stout gold leaf were employed to give the requisite body of metal.

Silver leaf.Burnished silver leaf was occasionally used by the mediaeval illuminators, though not very often, as it was very liable to tarnish and blacken. For this reason leaf tin was not unfrequently used instead of silver, as tin does not oxydize in such a conspicuous way; see above, p. 233.

The use of all three metals, gold, silver and tin, is described by Theophilus, Schedula diversarum Artium, I. 24, 25 and 26. Theophilus speaks of laying the gold leaf directly on to the vellum with the help only of white of egg. This method was not uncommon in early times, and it was not till the end of the thirteenth century that the full splendour of effect was reached by the help of the thick, hard mordant-ground.

Cheap methods.Inferior processes were sometimes used for the cheap manuscripts of later times. Thus tin leaf burnished and then covered with a transparent yellow lacquer or varnish made from saffron was used instead of gold.

Cennino and other writers describe a curious method of applying gold easily and cheaply. The illuminator was first to paint his design with a mixture of size and pounded glass or crystal; this, when dry, left a surface like modern sandpaper or glass-paper, the artist was then to rub a bit of pure gold over the rough surface, which ground off and held a sufficient amount of gold to produce the effect of gilding. Only a very coarse effect, worthy of the nineteenth century, could have been produced by this process.

CHAPTER XV.

The Materials and Technical Processes of the Illuminator (continued).

Vehicles used.The coloured pigments of the illuminators. Though mediaeval manuscripts are splendid and varied in colour to the highest possible degree, yet all this wealth of decorative effect was produced by a very few pigments, and with the simplest of media, such as size made by boiling down shreds of vellum or fish-bones^[264], or else gum-arabic, or occasionally white of egg or a mixture both of the yoke and the white^[265]. In the main the technique of manuscript illumination is the same as that of panel pictures executed in distemper (tempera). An oil medium was unsuited to manuscript work because the oil spoilt the beautiful opaque whiteness of the vellum and made the painting show through to the other side^[266].

Ultramarine blue.Blue pigments. The most important blue pigment, both during classical and mediaeval times, was the costly and very beautiful ultramarine (azzurrum^[267] transmarinum), which was made from lapis lazuli, a mineral chiefly imported from Persia. This ultramarine blue was the cyanus or coeruleum of Theophrastus and Pliny. It is not only the most magnificent of all blue pigments, but is also the most durable, even when exposed to light for a very long period.

Its manufacture.The general principle of the manufacture of ultramarine is very simple; consisting merely in grinding the lapis lazuli to powder, and then separating, by repeated washing, the deep blue particles from the rest of the stone^[268]. The process of extracting the blue was made easier if the lapis lazuli was first calcined by heat. This is the modern method, and was occasionally done in mediaeval times, but it injures the depth and brilliance of the pigment, and in the finest manuscripts ultramarine was used which had been prepared by the better though more laborious process without the aid of heat.

Its great value.The proportion of pure blue in a lump of lapis lazuli is much smaller than it looks; the stone was and is rare and costly, and thus the finest ultramarine of the mediaeval painters was often worth considerably more than double its weight in gold^[269].

Both in classical and mediaeval times it was usual for the patron who had ordered a picture to supply the necessary ultramarine to the artist, who was only expected to provide the less costly pigments in return for the sum for which he had contracted to execute the work.

Method of theft.Pliny (Hist. Nat. XXXIII. 120) tells a story of a trick played by a painter on his employer, who suspiciously watched the artist to see that he did not abstract any of the precious ultramarine which had been doled out to him. At frequent intervals the painter washed his brush, dipped in the ultramarine, in a vessel of water; the heavy pigment sank to the bottom, and at the end of the day the artist poured off the water and secured the mass of powdered ultramarine at the bottom.

It is interesting to note that Vasari, in his life of Perugino, tells precisely this story about Pietro, who was annoyed at the suspicions expressed by a certain Prior for whom he was painting a fresco^[270]. The Prior was in despair at the enormous amount of pigment that the thirsty wall sucked in, and he was agreeably surprised when, at the conclusion of the work, Perugino returned to him a large quantity of ultramarine, as a lesson that he should not suspect a gentleman of being a thief.

Ultramarine scraped off.The library of Corpus Christi College, Cambridge, possesses a manuscript which affords a curious proof of the great value of ultramarine to the mediaeval illuminator. This is a magnificent copy of the Vulgate by a German scribe of the twelfth century, copiously illustrated with miniature pictures, many of which had backgrounds, either partially or wholly, covered with ultramarine. All through the book the ultramarine has in mediaeval times been very carefully and completely scraped off, no doubt for use in another manuscript. This theft has been accomplished with such skill that wonderfully little injury has been done to the beautiful illuminations, except, of course, the loss of splendour caused by the abstraction of the ultramarine.

Impasto.In illuminated manuscripts ultramarine is very freely used. It is specially noticeable for the thick body (impasto) in which it is applied, so as very often to stand out in visible relief. The reason of this is that this, and some other blue pigments, lose much of their depth of colour if they are ground into very fine powder. Hence both the ultramarine and smalto blues are always applied in comparatively coarse grained powder; and this of course necessitates the application of a thick body of colour.

Ancient cyanus.Smalto blues. Next in importance to the real ultramarine come the artificial smalto or "enamel" blues, which were used largely in Egypt at a very early date under the name of artificial cyanus; see Pliny, Hist. Nat. XXXVII. 119. Among the Greeks and Romans too this was a pigment of great importance, and when skilfully made is but little inferior in beauty to the natural ultramarine.

Vitreous pigment.Smalto blue is simply a powdered blue glass or vitreous enamel, coloured with an oxide or carbonate of copper. Vitruvius (VII. xi. 1) describes the method of making it by fusing in a crucible the materials for ordinary bottle-glass, mixed with a quantity of copper filings. The alcaline silicate of the glass frit acts upon the copper, which slowly combines with the glass, giving it a deep blue colour. The addition of a little oxide of tin turns it into an opaque blue enamel, which when cold was broken up with a hammer, and then powdered, but not too finely, in a mortar.

Smalto blue is largely used for the simple blue initials which alternate with red ones in an immense number of manuscripts. The glittering particles of the powdered glass can easily be distinguished by a minute examination. Like the ultramarine, the smalto blue is always applied in a thick layer.

The monk Theophilus (II. 12), who wrote during a period of some artistic and technical decadence, the eleventh century, advises the glass-painter who wants a good blue to search among some ancient Roman ruins for the fine coloured tesserae of glass mosaics, which were so largely used by the Romans to decorate their walls and vaults, and then to pound them for use.

German blue.Azzurro Tedesco or Azzurro della Magna, German blue, was much used by the illuminators as a cheap substitute for ultramarine. This appears to have been a native compound of carbonate of copper of a brilliant blue colour. It was occasionally used to adulterate the costly ultramarine, but this fraud was easily discovered by heating a small quantity of the pigment on the blade of a knife; it underwent no change if it was pure; but if adulterated with Azzurro della Magna it showed signs of blackening^[271].

Indigo.Indigo blue. The above-mentioned blues are all of a mineral character, and are durable under almost any circumstances. To some extent however the vegetable indigo blue was also used for manuscript illuminations, both alone and also to make a compound purple colour.

Method of using dyes.Colours of all kinds prepared from vegetable or animal substances required a special treatment to fit them for use as pigments in solid or tempera painting. Though indigo and other colours of a similar class are the best and simplest of dyes for woven stuffs, yet they are too thin in body to use alone as pigments. Thus both in classical and mediaeval times these dye-pigments were prepared by making a small quantity of white earth, powdered chalk or the like absorb a large quantity of the thin dye, which thus was brought into a concentrated and solid, opaque form, not a mere stain as it would otherwise have been.

These kinds of pigments are described by Pliny, Hist. Nat. XXXV. 44 and 46; and by Vitruvius, VII. xiv. Eraclius in his work on technique, De artibus Romanorum, calls them colores infectivi, "dyed colours," an accurately expressive phrase.

One method, occasionally used for the cheaper class of manuscripts, was to paint on to the vellum with white lead, and then to colour it by repeated application of a brush dipped in the thin dye-pigment. Many of the colours mentioned below belong to this class.

Terra verde.Green pigments. A fine soft green much used in early manuscripts is a natural earthy pigment called terra verde or green Verona earth. This needs little preparation, except washing, and is of the most durable kind; it is a kind of ochre, coloured, not with iron, but by the natural presence of copper.

Verdigris green.A much more brilliant green pigment was made of verdigris (verderame) or carbonate of copper, produced very easily by moistening metallic copper with vinegar or by exposing it to the fumes of acetic acid in a closed earthen vessel; see Theophilus, I. 37.

Verdigris green was much used by manuscript illuminators, especially during the fifteenth century, when a very unpleasant harsh and gaudy green appears to have been popular. When softened by an admixture of white pigment, verdigris gives a pleasanter and softer colour.

Chrysocolla.A native carbonate of copper, which was called by the Romans chrysocolla^[272], was also used for mediaeval manuscripts. It is, however, harsh in tint if not tempered with white. Both the last-named pigments were specially used with yoke of egg as a medium.

Prasinum, a vegetable green made by staining powdered chalk with the green of the leek, was sometimes used.

Cennino Cennini also recommends a grass green made by mixing orpiment (sulphuret of arsenic) and indigo.

One of the best and most commonly used greens was made by a mixture of smalto blue and yellow ochre; other mixtures were also used.

Red pigments. Red and blue are by far the most important of the colours used in illuminated manuscripts, and it is wonderful to see what variety of effect is often produced by the use of these two colours only.

Vermilion and minium.The chief red pigments used by illuminators are vermilion (cinnabar or sulphuret of mercury) and red lead (minium), from which the words miniator and miniature were derived, as is explained above at page 31^[273].

Both these pigments are very brilliant and durable reds, the more costly vermilion is the more beautiful of the two; it has a slightly orange tint.

Mixed reds.Illuminators commonly used the two colours mixed. One receipt recommends one-third of red lead combined with two-thirds of vermilion; Jehan le Begue's manuscript, § 177 (Mrs Merrifield's edition, Vol. I. page 141). Vermilion was prepared by slowly heating together metallic mercury with sulphur. Red lead (a protoxide of lead) was made by roasting white lead or else litharge (ordinary lead oxide) till it absorbed a larger proportion of oxygen.

Ochre reds.Rubrica or Indian red was a less brilliant pigment, which also was largely used in illuminated manuscripts, especially for headings, notes and the like, which were hence called rubrics. Rubrica is a fine variety of red ochre, an earth naturally coloured by oxide of iron^[274]; another variety was called bole Armeniac. In classical times the rubrica of Sinope was specially valued for its fine colour.

In addition to these mineral and very permanent reds there were some more fugitive vegetable and animal scarlets and reds which were used in illuminated manuscripts.

Murex.Murex. One of these, the murex shell-fish, has already been mentioned for its use as a dye for the vellum of the magnificent Byzantine and Carolingian gold-written manuscripts. The murex was also used as a color infectivus by concentrating it on powdered chalk^[275].

Kermes.Kermes. Another very beautiful and important carmine-red pigment was made from the little kermes^[276] beetle (coccus) which lives on the ilex oaks of Syria and the Peloponnese. It is rather like the cochineal beetle of Mexico, but produces a finer and more durable colour, especially when used as a dye. For the woven stuffs of classical and mediaeval times, and in the East even at the present day, the kermes is one of the most beautiful and important of all the colours used for dyeing. The mediaeval name for the kermes red was rubeum de grana; when required for use as a pigment it appears to have been usual, not to extract the colour directly from the beetle, but to get it out of clippings of red cloth which had been dyed with the kermes, by boiling the cloth in a weak solution of alkali and precipitating the red pigment from the water with the help of alum.

The reason for this method is not apparent. Possibly it was first done as a means of utilizing waste clippings of the costly red cloth, and then, when the habit was established, no other method was known to the colour-makers, who in some cases bought pieces of cloth on purpose to cut them up and use in this way^[277]. The scarletum blanketum mentioned at page 234 was bought for this purpose.

Madder.Madder-red was also used as a pigment by boiling the root of the madder-plant (rubia-tinctorium), and then using the concentrated extract to dye powdered chalk. Various red and purple flowers, such as the violet, were used in the same way as colores infectivi.

Lac.Lake-red (lacca or lac) was made and called after a natural gum or resin, the lach of India; see Cennino Cennini, § 44.

This is a beautiful transparent colour, which, in some fine manuscripts of the fifteenth century, is used as a transparent glaze over burnished gold, the effect of which is very magnificent, as the metallic gleam of the gold shines through the deep transparent red of the over-painting. Lake was also used as an opaque, solid pigment by mixing it with white, which at once gave it "body," and destroyed its transparency.

Purple of a very magnificent tint was occasionally made by a mixture of ultramarine with the carmine-red of the kermes beetle; this was specially used by the illuminators of the fourteenth and fifteenth centuries.

Yellows.Yellow ochre, a fine earth pigment coloured by iron, was the principal yellow of the illuminators.

In late manuscripts orpiment (sulphuret of arsenic), which is a more brilliant lemon-yellow, was occasionally used; see Cennino Cennini, § 47.

Litharge yellow, an oxide of lead, was another important colour, but more especially for the painter in oil, who used it very largely as a drier^[278].

Another fine ochreous earth of a rich brown colour was the terra di Siena or "raw Siena"; the colour of this was made warmer in tint by roasting, thus producing "burnt Siena."

Use of white.White pigments were perhaps the most important of all to the illuminator, who usually only used pure colours for his deepest shadows; all lights and half tints, both in miniature pictures and in decorative foliage, being painted with a large admixture of white. The use of this system of colouring by Fra Angelico and many painters of the Sienese school has been already referred to; see page 190.

For this reason it was very important to use a pure and durable white pigment which would combine well with other colours.

Lime white.Bianco di San Giovanni was in all respects one of the best of the whites used by illuminators.

This was simply pure lime-white, made by burning the finest white marble; the lime was then washed in abundance of pure water, then very fine ground and finally dried in cakes of a convenient size; see Cennino Cennini, § 58; and Theophilus, I. 19. The medium used with it was the purest size or gum Arabic of the most colourless kind.

Another white pigment was made of powdered chalk and finely ground egg-shells; this was a less cold white than the bianco di San Giovanni.

White lead.White lead (cerusa or biacca) was also used^[279], especially by the later illuminators, but with very unfortunate results, since white lead is liable to turn to a metallic grey or even black if exposed to any impure sulphurous atmosphere.

Many beautiful manuscripts have suffered much owing to the blackening of their high lights which had been touched in with white lead; especially manuscripts exposed to the gas- and smoke-poisoned air of London or other large cities.

Process of manufacture.The biacca of the mediaeval illuminator was made in exactly the same way that Vitruvius and Pliny describe; see Vitr. VII. xii.; and Pliny, Hist. Nat. XXXIV. 175.

A roll of lead was placed in a clay dolium or big vase, which had a little vinegar at the bottom. The top was then luted down, and the jar was left in a warm place for a week or so, till the fumes of the acetic acid had converted the surface of the lead into a crust of carbonate. This carbonate of lead was then flaked off and purified by repeated grinding and washing.

In order to keep the white pigments perfectly pure, some illuminators used to keep them under water, so that no dust could reach them.

Black inks. Two inks of quite different kinds were used for the ordinary text of mediaeval manuscripts.

Carbon ink.One of these was a pure carbon-black (modern Indian or Chinese ink); this has been described under the classical name atramentum librarium^[280]; see above, page 27. The great advantage of this carbon ink is that it never fades; it is not a dye or stain, but it consists of very minute particles of carbon which rest on the surface of the vellum.

Iron ink.The other variety was like modern black writing ink, only of very superior quality. This acts as a dye, staining the vellum a little below the surface. Unfortunately it is liable to fade, though when kept from the light (as in most manuscripts) it has stood the test of time very well.

Sometimes the mediaeval illuminators distinguished these two kinds of black ink, calling the first atramentum and the second encaustum; but frequently the names are used indifferently for either: see Theophilus, I. 40. The encaustum was made by boiling oak-bark or gall-nuts, which are rich in tannin, in acid wine with some iron filings or vitriol (sulphate of iron). The combination of the iron and the tannin gives the inky black^[281]. Both these black inks were used with gum Arabic.

Beauty of the plain text.A great part of the beauty of mediaeval manuscripts is quite unconnected with their illumination. The plain portion of the text, from the exquisite forms of its letters and the beautiful glossy black of the ink on the creamy ivory-like vellum page, lighted up here and there by the crisp touch of the rubricator's red, is a thing of extraordinary beauty and charm. This perfection of technique in the writing and beauty of the letters lasted considerably longer than did the illuminator's art. Hence in some of the manuscripts of the period of decadence, executed during the fifteenth century, the plain black and red text is very superior in style to the painted ornament; and one cannot, in some cases, help regretting that the manuscript has not escaped the disfigurement of a coarse or gaudy scheme of illumination.

Red inks were of three chief kinds, namely the vermilion, red lead, and rubrica or red ochre, which have been already mentioned.

Purple ink.Purple ink was used largely, not often for writing, but for the delicate pen ornaments of the initials in certain classes of late Italian and German manuscripts. A vegetable pigment seems to have been used for this; the lines appear to be stained, and do not consist of a body-colour resting on the surface of the vellum.