Technical Methods Of Tempera Painting
( Originally Published 1913 )
ACCORDING to the testimony of Pliny, tempera painting, as practised by the ancients, was in-vented by Ludius, a Roman painter who lived in the time of Augustus (circa 50 B.C.), but it is certain that the Egyptians and other old nations were acquainted with tempera methods thousands of years before this date, and quite likely that they used the egg medium, as well as certain glues and gums, as binding vehicles for their colours.
The ancient Greek painters worked in two methods of panel painting, one of them being in the wax medium, and the other in tempera. Although we have no direct evidence as to the kind of size they tempered their colours with, when painting on dry surfaces, we may safely assume that egg-size would be one of the mediums, if not the usual one, and the ancient receipt was passed on to posterity, as it was the favourite medium used by the Byzantine Greeks, and by the Italians up to the fifteenth century, and even later, on panels, dry walls, and illuminated miniatures. Besides, we may be fairly sure that such a convenient and easily made tempera vehicle as egg-size, would be well known in classic times, and used in preference to glues, for the reason that, unlike the latter, it did not require to be kept hot when using it. It was therefore the most convenient, as well as the most perfect form of size for panel picture painting, or for any kind of painting on dry surfaces. It had also the property of drying very hard, so that it formed an almost waterproof surface on the painting, and there was no fear of the oil or spirit varnish which was applied to tempera pictures, to protect them, ever penetrating such a firm medium to injure the colours that were tempered with it.
Pliny mentions the use of egg-size as a gilder's mordant, and to mix with certain colours, and also its medical uses, but not in connection with its common use in tempera painting. This, however, should not be taken as a proof that egg-size was not a common tempera medium in his time.
Cennini's Treatise contains many references to the use and the making of tempera mediums for painting on panels and on dry walls, or a secco, as this method of painting is so named to distinguish it from other kinds, such as the wet, or buon fresco method.
The old painters, up to the time when oil painting superseded tempera for panel and canvas pictures, used several kinds of size to temper their colours, such as glue made from parchment, or from cuttings of horns, hoofs, and bones of animals, but not to any extent compared with the use of egg-size. The latter may be said to have been the favourite medium of all the early Italian and Flemish painters who executed their works on dry surfaces.
They used the egg medium, which was made in a variety of ways, namely :—The yolk of the egg beat up in clean water ; the yolk and white, or the whole egg beat up in water ; the white alone in water (this, however, was more frequently used as a preservative glaze over either tempera or oil pictures, and as a gilder's size), and the yolk alone, to which a little juice of the fig tree was added and the mixture thinned with water, or sometimes with vinegar or wine. Cennini mentions these forms of egg medium as being excellent for use in painting on panels and on dry walls. The terms " glue " or " egg-glue " were sometimes applied to the egg mediums. Water, or very weak size, is used to dip the brush in when painting in distemper.
PANEL PAINTING.—As regards the technical methods of painting in tempera on panels, the old Italian masters, following the Greek practice, prepared their painting grounds by sketching and fastening down canvas or linen cloth over wooden panels. The latter were previously prepared from boards or planks of well-seasoned timber of lime, poplar, or willow tree. The boards were sometimes dovetailed together, or joined by means of a strong glue, similar to the modern carpenter's glue, or with a glue made from a preparation of cheese and lime. The canvas cloth, either in one piece or in several strips, was stretched and glued on the surface of the board which, in cases of old work, had previously been coated with a thick gesso ground ; and on this gesso ground, while it was still in a soft or wet state, the canvas or linen was laid and so embedded in the soft gesso. On the cloth, when thoroughly dry, was spread several coatings of gesso, consisting of a mixture of chalk, whiting, or gypsum with glue size. The first coating was rough in texture, and when dry, a second or third coating of a finer texture was applied, which was brought to an exceedingly smooth and polished surface by scraping, filing, and glass-paper rubbing.
This provided a white, smooth, and absorbent ground, on which the drawing was outlined, or very carefully engraved. The painted flesh parts of the picture were then, generally speaking, treated with a solid or flat tint of grey green (verde), which formed a sort of middle tint, on which the lights and shades were painted in their proper places, by an elaborate system of careful stippling, or hatching in lines. The lights were usually of a warm tint, especially so in the older work, and the shadows a brownish or golden green, while rosy tints were stippled in for the carnations of the cheeks and lips. When all the modelling of the flesh tints, in light and shade, was so far accomplished, after great labour expended in getting the required roundness of forms, the whole work was covered with thin glazes of very trans-parent colour, which operation served to fuse the various tints, without destroying their crispness, into the required appearance of solidity. The transparent glazes would of course vary in hue, or be warm or cold, according to the general tone and effect aimed for. Glazes were used to a great extent by the early Sienese and Florentine painters, who worked in tempera on gesso grounds, for without the use of such glazes it would have been hardly possible for them to obtain that careful finish which characterizes their 'work, notwithstanding the elaborate stippling employed with the more solid colours.
Draperies in tempera paintings were executed in a more direct and franker method than that which obtained in flesh painting, for although a certain amount of stippling was often employed in drapery painting in order to get the required degree of finish, it was hardly ever done to the same extent in draperies as it was in flesh tints. Consequently, as a rule, the draperies in the old Italian pictures and wall paintings remain fresh, clear and bright, in contrast to most of the flesh painting, which in the course of time has become brownish, heavy, and dull.
The great difficulty experienced by the old painters, when working in tempera, to represent anything like the tints and tones of flesh colours, as they appear in nature, led to an elaborate system of stippling, hatching, and glazing, for the nature of the materials used, and the rapid drying of the medium, prevented the colours from being fused together before they had dried on the surface, and hence the resort to stippling and glazing. This difficulty will be better understood if we compare it with the comparatively easy way in which colours may be fused together in oil-painting methods, and which so produces a finished appearance without requiring any after stippling.
However brilliant and luminous the flesh colouring of the old tempera paintings may have been when first painted, it was inevitable from the numerous superimposed tints employed, in order to get some semblance of nature, and from the extremely delicate and laborious method of execution, that these portions of the work would in time become darker, yellower, or colder, and that the delicate hatchings and thin glazes would be easily abraded or destroyed by rubbings or cleaning.
On the other hand, draperies and other portions of tempera paintings being executed with a greater impasto of pigment in a solid and direct manner, have kept their colour and original effect better than the flesh portions, and the glazings on the draperies and accessories were nearly always applied in the nature of tinted varnishes, which further accounts for the good condition of these parts of the paintings.
Tempera paintings on panels, such as altar-pieces and portable pictures in frames, have lasted longer, and kept their original condition much better than tempera work on dry walls, though both may be executed, up to the final varnishing, in the same methods. The reason for this is easily understood, namely, that a protective varnish was always applied to pictures on wood or canvas, but which could not be used in wall tempera, without imparting an undesirable glossy surface. Tempera paintings on walls if not protected by a varnish do not last long, as we know by the bad state of such work wherever it has been done in conjunction with buon fresco. Unvarnished tempera, executed on wood, canvas, parchment or paper deteriorates also very quickly, unless it is well protected by glass, or kept en-closed as in a book from air, sunshine, dust, and from the liability of been rubbed.
In the best periods of Italian tempera painting, the fourteenth and fifteenth centuries, draperies were as a rule painted very simply, the artist usually mixing at first about three shades of the desired colour, one each for the broad lights, the middle tint, and the shadows. When the work was finished as far as possible with these three tints it would present a monochrome effect modelled in light and shade, when the final touches of sharp high lights and accents of deeper darks in some parts of the shadows would give the complete finish. Accidental colours that might be reflections from surrounding objects were rarely at-tempted, especially in the works of the Italian Primitives, although we often see that most of the Italian masters coloured the lights of certain draperies more or less in tones that were complementary to the general or local colour ; for example, green draperies would often have reddish lights, and blue draperies a warm yellowish, or warm greenish lights, etc. This practice was common until after Raffaelle's time with the Italian and also with the Flemish artists.
There is an interesting study of a man's portrait in the Dresden Gallery, by Pinturicchio, painted in tempera, about the end of the fifteenth century. This work furnishes a good example of tempera methods in flesh painting, as the mode of execution and the colours employed illustrate not only the tempera methods of that time, but might well serve as an illustration of such work that was done two or three centuries earlier. In this study we can see the usual grey green ground, verde (verdaccio), which has been laid on in a flat tint all over the face ; the modelling of the light and shade is obtained by the use of a yellowish red, and the rosy carnations are hatched in definite lines over the green, which is allowed to be clearly seen in the semitones ; darker and warmer hatchings are to be seen in the shadows, but evidently the work has not had the usual transparent glazings, which makes it all the more valuable as a highly interesting illustration of Italian tempera methods where glazings have not been used. This work has been varnished, and is in good condition.
The varnishes that have been used in tempera painting are described in Chapter. XII.
Some of the earliest examples of tempera painting in Central Italy are the painted Crucifixes of the eleventh and twelfth centuries ; one of the oldest of these is the colossal Crucifix in San Michele in Fero, at Lucca, and is the work of an artist of the eleventh century. The Saviour is represented as an erect and well-proportioned figure. The painting is in tempera, executed on a primed canvas, which is beaten into the gesso ground that covers the wood foundation. Some parts of the figure are raised in relief, and the work is therefore a combination of plastic and flat methods of execution, like many others of the eleventh and twelfth centuries. In some instances, in those days, these Crucifix paintings were executed on parchment stretched on the wood, instead of canvas.
The flesh colours in the earlier Crucifixes were either of a uniform yellowish brown colour, or of a dull flesh tint with green half-tones and reddish shadows. As a general rule, in many other Lucchese Crucifix paintings the chief features of the execution consist in the rendering of the modelling of the flesh tones by parallel or con-centric lines of red, blue and white, with the anatomical articulations in black. The preparation colour for the flesh was usually a grey green, or verde (verdaccio), which was similar to the tint used as a half-tone, or middle-tint, by the later Italian artists in their flesh painting, especially in panel pictures.
Early Sienese art is noted for its mixture of relief-work and painting ; in some cases glass stones were embedded in the nimbi of the saints and in other parts of the accessories. Gold was frequently used for backgrounds, and as shot lines in draperies to enrich them, as well as for the nimbi of saints, and in various ornaments.
Prior to and during the time of Giunta, of Pisa, who lived in the first half of the thirteenth century, the practice of stretching canvas or linen cloth and fastening it on wood with glue was a very common one with the Byzantine painters, who no doubt learned this method of preparing painting grounds from the Greeks and Romans, and who in their turn followed the Egyptians, to whom this method was well known.
There is an interesting example of a painting executed on canvas, stretched and embedded in gesso on a wood panel, consisting of an altarpiece by the painter Margaritone of Arezzo, in the National Gallery (No. 564). Margaritone was born in 1236, and this masterpiece of his is still in good condition. It affords a proof that paintings executed in tempera on a gesso ground spread on canvas, which has been securely glued to a wood panel, have lasted longer than works which have been executed in almost any other method. Vasari, writing in the sixteenth century, speaks of this altarpiece by Margaritone, and expresses his surprise that " a picture on canvas should have lasted so long." It is now more than another three centuries older, and is still in a good state of preservation. We cannot be surprised at this, when we find that the Egyptian coffin paintings, which have been executed in a similar method, are still well preserved after a period of four or five thousand years. Modern artists might be safely advised to adopt this time-tested method of preparing their painting grounds.
Tempera painting, either on wood or on canvas, was the favourite method of the Italian painters from the earliest times up to the adoption of oil painting in Italy, and was carried to great perfection in the works of Ghirlandaio (1449–1494) and Botticelli (1444 ?-1510).