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and in any case limited use of oil, tempera was in constant employment till in the fifteenth century it began to be superseded by the new oil media popularized by the van Eycks.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 In the case of mural work at any period fresco can really never have wholly superseded tempera, for fresco can only be worked on fresh plaster, while the artist must often have to decorate walls already plastered and long ago dry.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.

[§ 83, _Oil Painting, its Discovery and Early History_, ante, p. 226.]

The bare fact of the invention of oil painting by John of Bruges, recorded by Vasari in 1550 in