Vasari on technique

Of Niello,^[279] and how by means of this process we have Copper Prints; and how Silver is engraved to make Enamels over bas-relief, and in like manner how Gold and Silver Plate is chased.^[280]

§ 103. Niello Work.

Niello, which may be described as a design traced and painted on silver, as one paints and traces delicately with the pen, was discovered by the goldsmiths as far back as the time of the ancients, there having been seen in their gold and silver plates incisions made by tools and filled up with some mixture.^[281] In niello the design is traced with the stylus on silver which has a smooth surface, and is engraved with the burin, a square tool cut on the slant like a spur from one of its angles to the other; for sloping thus towards one of the corners makes it very sharp and cutting on the two edges, and its point glides over the metal and graves extremely finely.^[282] With this tool is executed all graving on metal, whether the lines are to be filled or are to be left open, according to the pleasure of the artificer. When therefore they have finished their graving with the burin, they take silver and lead and fuse them into one substance over the fire; and this when completely amalgamated is black in colour, very friable, and extremely fusible.^[283]

The next process is to pound this substance and put it over the engraved silver plaque which must be thoroughly clean, then to bring it near to a fire of green wood, blowing with the bellows that the rays of the fire may strike upon the niello, which by virtue of the heat melts and flows filling up all incisions that the graver has made. Afterwards when the silver has cooled, the worker proceeds to remove carefully the overplus with scrapers, and with pumice stone to grind it away little by little, rubbing it with the hands and with a leather till it is reduced to the true flat and the whole is left polished. The Florentine Maso Finiguerra worked most admirably in this craft in which he was really extraordinary, as is testified to by some paxes^[284] of niello in San Giovanni of Florence that are esteemed wonderful.

§ 104. The Origin of Engraving.

From this graving by the burin are derived the copper plates from which we see to-day so many impressions throughout all Italy of both Italian and German origin. Just as impressions in clay were taken from silver plaques before they were filled with niello, and casts pulled from these in sulphur,^[285] in the same manner the printers found out the method of striking off the sheets from the copper plates with the press, as we have seen printing done in our own days.

See now another sort of work in silver and in gold, commonly called enamel, a kind of painting intermingled with sculpture, suitable for lining the bottom of pieces intended to hold water.^[286] This when worked on gold, needs the very finest gold; and when on silver, the silver at least of the quality of the giulio.^[287] The following method is necessary in order that the enamel may remain in its place and not run beyond its proper limits. The edges of the silver^[288] must be left so fine that when looked at from above they escape the eye. In this way is made a flat relief contrary to the other kind,^[289] in order that when the enamels are put over it, it may take its darks and lights from the height and depth of the intaglio. Then glass enamels of various colours are picked out and carefully fixed with the hammer;^[290] they are kept in little bowls filled with clear water, separated and distinct one from the other. Those which are used with gold are different from those that serve for silver^[291] and they are worked in the following manner. The enamels are lifted out separately with the most delicate little silver shovel and spread in their places with scrupulous cleanliness, and this is done over and over again, according as the enamel adheres properly, and so with all the quantity that is needed at the time. This done, an earthenware receptacle, made on purpose, is prepared; it must be perforated all over and have a mouthpiece in front, then the muffle, which is a little perforated earthenware cover that will prevent the charcoal falling from above, is introduced into this receptacle, and above the muffle the space is filled up to the top with oak charcoal kindled in the ordinary way. In the empty space which is left under the aforenamed cover the enamelled object is placed on a very thin iron tray to feel the heat gradually and is kept there long enough to admit of the enamels melting, when they flow all over almost like water. Which done, it is allowed to cool, and then with a ‘frassinella,’ that is, a stone for sharpening iron tools, and with sand such as is used for drinking glasses moistened with clear water, it is rubbed till it becomes perfectly level. When the process of removing all superfluity is finished, the object is placed in the actual fire, to be melted a second time in order that the whole surface may become lustrous.^[292] Another sort is made by hand, and polished with Tripoli plaster (powder) and a piece of leather, but of this there is no need to make mention.^[293] I have however described the above because being, like the other processes, of the nature of painting it seemed to come into our subject.

§ 106. Metal Inlays.

In imitation of the ancients, the moderns have revived a species of inlaying in metals, with sunk designs in gold or silver, making surfaces either flat or in half or low relief; and in that they have made great progress. Thus we have seen works in steel sunk in the manner of tausia, otherwise called damascening, because of its being excellently well done in Damascus and in all the Levant. Wherefore we have before us to-day many bronzes and brasses and coppers inlaid in silver and gold with arabesques, which have come from those countries; and among the works of the ancients we have observed rings of steel, with half figures and leafage very beautiful. In our days, there is made in this kind of work armour for fighting all worked with arabesques inlaid with gold, also stirrups and saddle-bows and iron maces: and now much in vogue are such furnishings of swords, of daggers, of knives and of every weapon that men desire to have richly ornamented. Damascening is done in this way. The worker makes undercut sinkings in the iron^[295] and beats in the gold by the force of a hammer, having first made cuttings or little teeth like those of a slender file underneath, so that the gold is driven into these hollows and is fixed there.^[296] Then by means of tools, he enriches it with a pleasing design of leaves or of whatever he fancies. All these designs executed with threads of gold passed through the wire-drawing plate^[297] are twined over the surface of the iron and beaten in with the hammer, so as to be fixed in the method mentioned above. Let care however be taken that the threads are thicker than the incised outlines so as to fill these up and remain fixed into them. In this craft numberless ingenious men have executed praiseworthy things which have been esteemed marvellous; and for this reason I have not wished to omit mention of it, for it depends on inlaid work and so, partaking of the nature of both sculpture and painting, is part of the operations of the art of design.

Of Wood Engraving and the method of executing it and concerning its first Inventor: how Sheets which appear to be drawn by hand and exhibit Lights and Half-tones and Shades are produced with three Blocks of Wood.

§ 107. Chiaroscuro Wood Engravings.

The first inventor of engraving on wood in three pieces for showing not only the design but the shadows, half tints, and lights also was Ugo da Carpi.^[298] He invented the method of wood engraving in imitation of the engravings on copper, cutting them on the wood of the pear tree or the box which are excellent above all other kinds of wood for this work. He made his blocks then in three pieces,^[299] placing on the first all that is contour and line; on the second all that is tinted near to the outline, putting in the shadow with water colour; and on the third the lights and the ground leaving the white of the paper to give the light, and tingeing the rest for the ground. This third block containing the light and the ground, is executed in the following manner. A sheet printed by the first block, on which are all the contours and lines, is taken wet and placed on the plank of the pear tree and weighted down with other sheets which are not damp and so pressed upon that the wet sheet leaves on the board the impression of all the outlines of the figures. Then the painter takes white lead mixed with gum and puts in the lights on the pear-wood. After this is done the engraver cuts them all out with tools, according as they are marked. This block is that which, duly primed with oil colour,^[300] is used for the first process, namely, to produce the lights and the ground, the whole surface, therefore, is left tinted except just where it is hollowed out, because there the paper remains white. The second block is that which gives shadows. It is quite flat and tinted with water colour, except where the shadows are not to come, because there the wood is hollowed out. And the third, which is the first to be shaped, is that in which the whole outlined part is hollowed out all over, except where there are no profiles touched in with black by the pen.^[301]

These are printed at the press and are put under it three times, i.e. once for each impression, so that they shall severally have the same pressure. And certainly this was a most beautiful invention.

§ 108. Dependence on Design of the Decorative Arts.

All these lines of work and ingenious arts, as one sees, are derived from design, which is the necessary fount of all, for if they are lacking in design they have nothing.^[302] Therefore although all processes and styles are good, that is best by which every lost thing is recovered and every difficult thing becomes easy: as we shall see in reading the Lives of the artists, who, aided by nature and by study have done superhuman things solely by means of design. And thus, making an end of the Introduction to the three Arts, treated perhaps at too great length, which in the beginning I did not intend, I pass on to write the Lives.

The fresco process is generally regarded as one of several methods for the production of pictures. It is better to consider it in the first place as a colour finish to plaster work. What it produces is a coloured surface of a certain quality of texture and a high degree of permanence, and it is a secondary matter that this coloured surface may be so diversified as to become a picture.

The history of the process is involved in obscurity, and it is not known who first observed the fact that colours mixed only with water when laid on a wet surface of lime plaster dried with the plaster and remained permanently attached to it. The technique was however known to the Romans, and we obtain the best idea of its essential character from the notice of it by Vitruvius in the third chapter of his seventh book. It is there treated in intimate connection with plaster work, as only the last stage in the technical treatment of a wall. The wall is constructed of stone or brick; it is then plastered; and the plaster is, or can be, finally finished with a wash of colour. Of the character of this antique plaster work something has already been said in a note to § 72, in connection with Sculpture (ante, p. 171). It could be finished either in a plain face of exquisite surface that might even be polished, or with stamped ornaments in relief or figures modelled by hand; but it could also be completed with colour in the form either of a plain tint or a picture, and this colour would be applied by the fresco process.

Painting ‘a fresco’ means painting on the freshly laid and still wet final coat of plaster. The pigments are mixed with nothing but pure water, and the palette of the artist is limited by the fact that practically speaking only the earth colours, such as the ochres, can be used with safety; even the white has to be made from lime—the Italians called it ‘bianco San Giovanni’—as lead white, called ‘biacca,’ is inadmissible. Vegetable and metallic pigments are as a rule excluded from use. The reason why pigments mixed with water only, without any gum or similar binding material, adhere when dry to the plaster is a chemical one. The explanation of it was given by Otto Dönner in an Appendix to Helbig’s Campanische Wandgemälde, Leipzig, 1868, and is to be found also in Professor Church’s Chemistry of Paints and Painting. When limestone is burnt into lime all the carbonic acid is driven out of it. The result of the slaking of the lime by water, which is preliminary to its use in plastering, is that the material becomes saturated with an aqueous solution of hydrate of lime. This hydrate of lime rises to the surface of the plaster, and when the pigment is laid on, to use Professor Church’s phrasing, it ‘diffuses into the paint, soaks it through and through, and gradually takes up carbonic acid from the air, thus producing carbonate of lime, which acts as the binding material.’ To put the matter in simpler language, lime when burnt loses its carbonic acid, but gradually recovers it from the air, and incidentally this carbonic acid, as it is re-absorbed, serves to fix the colours used in the fresco process. It is a mistake to speak of the pigment ‘sinking into the wet plaster.’ It remains on the surface, but it is fixed there in a sort of crystalline skin of carbonate of lime which has formed on the surface of the plaster. This crystalline skin gives a certain metallic lustre to the surface of a fresco painting, and is sufficient to protect the colours from the action of external moisture, though on the other hand there are many causes chemical and physical that may contribute to their decay. If however proper care have been taken throughout, and atmospheric conditions remain favourable, the fresco painting is quite permanent.

The process of painting, it will be easily seen, must be a rapid one, for it must be completed before the plaster has time to dry, which it would do if left for a night. Hence only a certain portion of the work in hand is undertaken on each day and only so much of the final coat of plaster, called by the Italians ‘intonaco,’ is laid by the plasterer as will correspond to the amount the artist expects to cover before nightfall. At the end of the day’s work, the plaster not painted on is cut away round the outline of the work actually finished, and the next morning a fresh patch is laid on and joined up as neatly as possible to that of yesterday. In the making of these joints the ancient plasterer seems to have been more expert than the Italians of the Renaissance, and the seams are often pretty apparent in frescoes of the fifteenth and sixteenth centuries, so that they can be discerned in a good photograph. When they can be followed, they furnish information, which it is often interesting to possess, as to the amount that has been executed in a single day.

To prevent loss of time it is necessary to have a full-sized cartoon in readiness so that the drawing can be at once transferred to the coat of wet plaster as soon as it has been laid. Vasari speaks of these cartoons in § 77, in the second chapter on Painting, ante, p. 213. The use of the iron stylus for impressing the lines of the drawing on the wet plaster is to be traced in some of the later Italian frescoes. Another process for carrying out the transfer was called ‘pouncing.’ For this the lines of the cartoon were pricked and dabbed with a muslin bag filled with powdered black, so as to show in dotted contours upon the wall.

Vasari is eloquent, both here and in a passage in his ‘Proemio’ to his whole work, on the judgement, skill, and decision necessary to paint successfully in fresco under these conditions and within these limits of time. The ideal of the process was to complete each portion absolutely at the one sitting. When the wall is once dry, any retouching, reinforcement of shadows, and the like, must be done ‘a secco,’ ‘on the dry,’ that is with pigments mixed with size, egg, or some other tempera, which will bind them to the surface. These after-touches lack the quality of texture and permanence of the true fresco (buon fresco). If size or gum have been used, they can be washed off the wall, and having been laid on a dry surface by a kind of hatching process they are harsh and ‘liney.’ It is often possible in good large-scale photographs to distinguish between the broad soft touches of the frescoist laid on while the ground was wet, and the hard dry hatchings of the subsequent retouching.

The illustration, Plate XV, has been chosen as a good example of the fresco technique. It shows the head of Mary from Luini’s fresco of the ‘Marriage of the Virgin’ at Saronno. The painting is executed in a broad and facile manner, the tints and tones which give the colour and the modelling being deftly fused while the whole is wet, and the darker details, such as the locks of the hair, are struck over the moist ground so that the touches seem soft and have no appearance of hatching. The light-coloured leaves of the garland round the head show the same softness, and they are laid in with a full brush in thick pigment. On the other hand there are marks of retouching where the shadows round the eyes, the corner of the mouth, etc., have been reinforced ‘a secco,’ perhaps by a restorer. These show as thin, hard, wiry lines, and have quite a different appearance from the work on the wet plaster.

It was only in the palmy days of Italian painting, from the latter part of the fifteenth century onwards, that artists were able to dispense almost entirely with retouching. In the earlier period of Giotto and his successors much more was left to be done ‘a secco,’ but the Giottesques fully understood the importance of doing all they could on the wet plaster, and Cennini in the 67th chapter of his Trattato insists that ‘to paint on the fresh, that is a fixed portion on each day, is the best and most permanent way of laying on the colour, and the pleasantest method of painting.’ The truth is that the technique of ‘buon fresco,’ while apparently understood by the Romans, was lost in the west during the early middle ages, though it may have been maintained in the Byzantine cloisters. In the course of the progressive improvements in the art of painting in the fourteenth and fifteenth centuries the old technique was gradually recovered. Recently Ernst Berger, in his Beiträge zur Entwicklungs-Geschichte der Maltechnik, I and II, München, 2nd ed., 1904, has denied that the Romans used the fresco technique, and has evolved an ingenious theory of a derivation of fresco painting from the mural work in mosaic which flourished in the Early Christian centuries. See note, ante, p. 255. Into the question thus raised it is not necessary to enter, because no reader of Vitruvius or Pliny can have the shadow of a doubt that they knew and were referring to the fresco process. The words of Vitruvius (VII, iii) ‘Colores autem, udo tectorio cum diligenter sunt inducti, ideo non remittunt sed sunt perpetuo permanentes, quod calx,’ etc., and those of Pliny (XXXV, 49) ‘udo inlini recusant’ employed of certain colours which are known not to be admissible in fresco are quite conclusive on this point, and it does not advance science to build up elaborate theories on a denial of obvious facts.

In his appreciation of technical processes Vasari, it will be seen, reserves his enthusiasm for fresco painting, but gives oil the advantage over tempera (ante, p. 230) in that it (1) ‘kindles the colours,’ i.e., gives them greater brilliancy; (2) enables the artist to blend his pigments on the panel or canvas so as to secure a melting, or as the Italians say a ‘sfumato’ or ‘misty’ effect; (3) admits of a force and liveliness in execution which makes the figures seem in relief upon the surface, and finally (4), as he says at the beginning of chapter VII, is a great convenience, ‘una gran comodità all’arte della pittura.’ The only corresponding advantages on the side of tempera, as detailed in § 82, ante, p. 223 f., are the facts that all pigments can be used in it, and that the same media serve for work on grounded or ungrounded panels or on the dry plaster of walls; and that paintings in tempera are very lasting. When Vasari came to write of his own works at the end of the Lives in the second edition, his conscience seems a little to have smitten him, and he gives the process a word of special commendation. He speaks of using it for some mural paintings in his private house which he had just built at Arezzo, and says, ‘I have always reverenced the memory and the works of the ancients, and seeing that this method of colouring “a tempera” has fallen out of use, I conceived the desire of rescuing it from oblivion. Hence I did all this work in tempera, a process that certainly does not merit to be despised or neglected’ (Opere, VII, 686).

If antiquity and wide diffusion be criteria of rank among painting processes, then tempera may claim the first place of all. The Spaniard Pacheco, the father-in-law and teacher of Velasquez, remarks on the veneration due to it because it had its birthday with art itself. As a fact all the wall paintings in ancient Egypt and Babylonia and Mycenaean Greece, all the mummy-cases and papyrus rolls in the first-named country, are executed in tempera, and the same is probably true of all the wall paintings in Italian tombs, as well as of the lost mural work of Polygnotus and his school, and the panel paintings of all the Greek artists save those who, in the later period after Alexander, adopted encaustic. Though fresco was known as a mural process to the Romans it was not used in the Early Christian catacomb paintings, nor in the mediaeval wall paintings north of the Alps, for all these were in tempera. For panel painting, both in the East and the West, save for a doubtful and in any case limited use of oil, tempera was in constant employment till in the fifteenth century it began to be superseded by the new oil media popularized by the van Eycks. Even then tempera maintained its ground, and it is not always realized that artists like Mantegna, Botticelli and Dürer were as a rule in their panel work tempera painters. In the case of mural work at any period fresco can really never have wholly superseded tempera, for fresco can only be worked on fresh plaster, while the artist must often have to decorate walls already plastered and long ago dry. In this case there would be a choice between replastering for fresco and the more economical alternative of employing some form of tempera.

It is however with tempera painting on panels rather than with mural work that we are here concerned. Vasari’s summary treatment of the process in § 82 ante, p. 223, contrasts with Cennini’s far more elaborate directions, and is a measure of the destructive effect of the inroad of oil painting on the more venerable system. At the outset of his Trattato Cennini gives a list of the processes the panel painter has to go through. The preliminary ones, before painting actually begins, will take him six years to learn and Cennini needs about a hundred chapters to describe them. The artificer must know how to grind colours, to use glue, to fasten the linen on the panel, to prime with gesso, to scrape and smooth the gesso, to make reliefs in gesso, to put on bole, to gild, to burnish, to mix temperas, to lay on grounding colours, to transfer by pouncing through pricked lines, to sharpen lines with the stylus, to indent with little patterns, to carve, to colour, to ornament the panel, and finally to varnish it! All this suggests, what was actually the case, that the process of tempera painting was a very precise and methodical one, proceeding by regular stages according to traditional methods and recipes. The result was from the point of view of modern painting something very limited, but within its range, and in the hands of artists of the fifteenth century, it was a very finished and exquisite artistic product, one indeed to which we return with ever-renewed delight after our yearly visits to the Salon or to Burlington House. A certain natural reaction, that some artists of to-day have felt against the slashing impressionistic style, has led to a revival of the old precise technique, which is now cultivated in London in a Society of Painters in Tempera. It should be remembered that it is perfectly possible to paint ‘a tempera’ in a free and loose fashion with a full impasto and individualistic handling. If dry powdered colours be mixed with the yolk or whole inside of an egg without dilution, the resulting pigment is as full of body as oil paint and can be manipulated in the same fashion. What is generally understood however by the tempera style is the painting of the fifteenth century on panel, in which, as Cennini indicates, the egg would be diluted with about its own bulk of water. This rendered the pigment comparatively thin and as a result transparent, and allowed coat to be laid over coat, so that Cennini contemplates seven or eight or even ten coats of colour tempered with egg yolk diluted with water. These are laid over an underpainting in a monochrome of terra verte, and are so transparent that even at the end the ground will remain slightly visible (c. 147) and so help the modelling. It is however a difficulty in tempera that it dries very quickly, too quickly to admit of that fusing of the tints while the impasto is wet, which Vasari mentions as an advantage in the oil process, § 83, ante, p. 230. Hence the usual ways to model in tempera are (1) to superimpose coats varying in tone, and (2), to use hatching, a process very observable in early Italian temperas, such as some ascribed to Botticelli in the National Gallery. Another drawback, not so marked however in egg tempera as in the size tempera with a basis of whitening used by scenic artists, is that the colours dry lighter than they appear when wet. Those who in the present day are enamoured of the tempera process say that these inconveniences do not trouble them, while they delight in the purity of the tints, the precision of the forms, which it enables them to preserve, and in a certainty and reposefulness which seem to belong to it. One of these writes as the result of her experience ‘In tempera you work with solid paints, and blending must be extremely rapid, or a substitute for this must be found in thin washes or in hatching. Crisp work is again a great beauty, but from the rapid drying of the paint in the brush, and its un-tenacious quality, it is a difficulty. Vasari is right in saying oil is a great convenience, but its introduction does not seem to have been in all respects a gain.’

OIL PAINTING.

The bare fact of the invention of oil painting by John of Bruges, recorded by Vasari in 1550 in chapter VII of his ‘Introduction’ to Painting, is in the Life of Antonello da Messina, in the same edition, retold in the personal anecdotic vein that accords with Vasari’s literary methods. Here the ‘invention’ followed on the splitting of a particular tempera panel, varnished in oil, that according to traditional practice van Eyck had put out in the sun to dry. The said artist then turned his attention to devising some means for avoiding such mischances for the future, and, in Vasari’s words, ‘being not less dissatisfied with the varnish than with the process of tempera painting, he began to devise means for preparing a kind of varnish which should dry in the shade, so as to avoid having to place the pictures in the sun. Having made experiments with many things both pure and in compounds, he at last found that linseed and nut oil, among the many which he had tested, were more drying than all the rest. These therefore, boiled with other mixtures of his, made him the varnish which he had long desired.’ This varnish, Vasari goes on to say, he mixed with the colours and found that it ‘lit up the colours so powerfully that it gave a gloss of itself,’ without any after-coat of varnish.

If we ask What is the truth about this ‘invention’ of van Eyck, or of the brothers van Eyck (see ante, p. 226, note 1), the first answer of any one knowing alike the earlier history of the oil medium and Vasari’s anecdotal predilections would be ‘there was no invention at all.’ The drying properties of linseed and nut oil, and the way to increase these, had been known for hundreds of years, as had also the preparation of an oil varnish with sandarac resin. There is question too of a colourless spirit varnish, and of the process of mixing varnish with oil for a painting medium, in documents prior to the fifteenth century. The technique of oil painting is described by Theophilus, about 1100 A.D.; in the Hermeneia or Mount Athos Handbook; and in the Trattato of Cennini, while numerous accounts and records of the thirteenth and fourteenth centuries establish incontestably, at any rate for the lands north of the Alps, the employment of oils and varnishes for artistic wall and panel painting. The epitaphs for the tombs of the two van Eycks make no mention of such a feat as Vasari ascribes to them, and it is quite open to any one to argue, as is the case with M. Dalbon in his recent Origines de la Peinture à l’Huile, Paris, 1904, that it was no special improvement in technique that brought the van Eycks their fame in connection with oil painting, but rather an artistic improvement that consisted in using a traditional process to execute pictures which in design, finish, beauty, and glow of colour, far surpassed anything previously produced in the northern schools. There is a good deal of force in this view, but at the same time it is impossible to deny to the van Eycks the credit of technical improvements. They had a reputation for this long before the time of Vasari. In 1456, fifteen years after the death of the younger brother Jan, Bartolomeo Facio of Spezia wrote a tract De Viris Illustribus in which he spoke of John van Eyck as specially ‘learned in those arts which contributed to the making of a picture, and on that account credited with the discovery of many things in the properties of colours, which he had learned from ancient traditions recorded by Pliny and other writers.’ The Florentine Filarete, c. 1464, knew of the repute of Jan van Eyck in connection with the oil technique. Hence we may credit the van Eycks with certain technical improvements on traditional practices and preparations in the oil technique, though these can hardly be termed the ‘invention of oil painting,’ while their artistic achievement was great enough to force into prominence whatever in the technical department they had actually accomplished.

The question of the exact technique of the van Eycks, in its relation to the oil practice before their time, is one that has occupied many minds, and is not yet satisfactorily settled. Most of those who have enunciated theories on the subject have proceeded by guess-work, and have suggested media and processes that may possibly have been used, but for the employment of which there is no direct evidence. The most recent suggestion is that of Principal Laurie of Edinburgh, and this is founded on scientific analysis. The experiments with oils and varnishes and other media, which this investigator has been carrying on for many years, have taught him that the most secure substance for ‘locking-up’ pigments as the phrase goes, that is for shielding them from the access of moisture or deleterious gases, is a resin, like our Canada balsam, that may be used as a varnish or painting medium when dissolved in an essential oil. As he believes he can detect in the van Eycks’ extant pictures pigments that would only have lasted had they been shielded by a preparation of the kind, he conjectures that the use of a natural pine balsam, with probably a small proportion of drying oil and rendered more workable by emulsifying with egg, may be the real secret of which so many investigators have been in search. For example, the green used for the robe of John Baptist and other figures in the ‘Adoration of the Lamb’ at Ghent can be matched, as we lately found by experiment, with verdigris (dissolved in pine balsam which is a much finer green than verdigris ground in oil) and yellow ochre or orpiment, and the only known way of rendering verdigris stable is to dissolve it in these pine balsams, according to a recipe that is actually preserved in the de Mayerne MS., which Berger has lately printed in full in the fourth Part of his Beiträge.

Be this as it may, one thing is certain, that the oil painting of the van Eycks and other painters of the early Flemish school did not differ greatly if at all in its artistic effect from the tempera that had preceded it, and that is described in the last note. Oil painting, in the sense that we attach to the term, is really the creation not of the Flemings, nor of the Florentines and other Italians who were the first to try experiments with the new Flemish process, but of Giovanni Bellini and the other Venetians who adopted the oil medium in the last quarter of the fifteenth century. According to Vasari, ante, p. 229, and Life of Antonello da Messina, Opere, II, 563 f., it was the last named artist who acquired the secret of the invention of van Eyck through a visit to Flanders, and brought it to Venice. Vasari has been proved to be wrong in the chronology he gives of the life of Antonello, who was born about 1444 and was therefore much younger than Vasari makes him, and many critics have been disposed to relegate his whole account of the Sicilian painter to the realm of myth. The most recent authority on the subject however, Dr von Wurtzbach, in his Niederländisches Künstler-Lexicon, vindicates Vasari’s accuracy in the main points of the visit to Flanders and the introduction of the new process at Venice, which event may be fixed about 1475. It was taken up with avidity by the Bellini and by other Venetians of the time, and it is to the younger Bellini more than to any other painter that is due the apprehension of the possibilities latent in the oil medium. Giovanni Bellini began to manipulate the oil pigments with a freedom and a feeling for their varied qualities of which earlier oil painters had possessed little idea, and the way was prepared for the splendid unfolding of the technique in the hands of Giorgione, Palma, and Titian.

The external decorations, of which Vasari writes in chapters XI, XII, and XIII of his ‘Introduction’ to Painting, have come down to us in a very dilapidated condition, but there are still to be seen specimens of all the work he there describes, as well as of the decorative carvings in stone noticed in the ‘Introduction’ to Architecture, under the head of Travertine (at Rome) § 12, Istrian stone (at Venice) § 15, and Pietra forte (at Florence) § 17; ante, pp. 51, 56, 60. The most common technique is monochrome painting ‘a fresco’ on the plaster, and a good deal that passes as sgraffito is really only painted work in which there is no relief. One of the best existing displays is that on the façade of the Palazzo Ricci, at Rome, a little to the west of the Palazzo Farnese. Here on the top floor are painted trophies of armour in bronze colour (ante, p. 241) with grotesques (ante, p. 244) in yellow and brown on the story below. On the piano nobile there is a frieze of figures in grisaille monochrome, with some single figures on a larger scale between the windows. Above the door is another frieze of figures on a black ground. More extensive, but less varied and not so well preserved, are the figure compositions on the back of the Palazzo Massimi, in the Piazza dei Massimi, at Rome, where the whole wall is covered with figure monochromes on a large scale on dark grounds. There are many more fragmentary specimens, as in the Via Maschera d’ Oro, No. 7; the Via Pellegrino, No. 66, etc. The work of Maccari, Roma, Graffiti e Chiaroscuri, Secolo XV, XVI, gives a large collection of reproductions of work that has now to a great extent perished.

Sgraffito-work, in which the effect is produced by differences of plane in the plaster itself (see ante, p. 243), resists the weather much better than mere painting, but it takes longer to execute and was not so much used as the more rapidly wrought fresco. The Palazzo Montalvo, in the Borgo degli Albizzi at Florence, offers a good example of a compromise. The work, at any rate in the lower part, is not true sgraffito as the plaster in the backgrounds is not scraped away, but the outlines of the figures and ornaments are marked by lines incised in the plaster, the brush, with light and dark tints, accomplishing the rest. On the other hand the house of Bianca Capello, 26 in the Via Maggio, is decorated in the true sgraffito technique as described by Vasari, ante, p. 243. The same may be said of a house in Rome, Via Maschera d’ Oro, No. 9, where the difference of the two planes of plaster is about an eighth of an inch. This work is clogged up with buff lime-wash and would be worth cleaning, as it seems in fair preservation.

Of modelled stucco figure designs and grotesques the Cortile of the Palazzo Spada, near the Campo di Fiore at Rome, presents the most extensive display. A more interesting piece of work will however be found not far away in the Via de’ Banchi Vecchi, Nos. 22–24, the house of the goldsmith Pietro Crivelli of Milan, of the first half of the sixteenth century. Here between the windows of the first floor are boldly designed trophies of arms carved in travertine, while between and above the windows of the second floor there are figures and grotesques effectively modelled in stucco. These are outlined with an incised line in the stucco and there is no colour. For free but not over-florid Renaissance enrichment the façade is noteworthy. The abundant stone carving at Florence in the form of the ‘stemmi’ has been already referred to, ante, p. 61.

STUCCO ‘GROTESQUES.’