As we shall have occasion, in the following pages, to speak of fresco, secco, and tempera, as distinguished from oil painting, it will be wise to try and understand clearly what these methods of work are, and in what respects they differ from, exceed, or fall short of, the modern practice.

Tempera[22] is the old name for any vehicle used in painting. The two great divisions of painting in the Middle Ages were fresco and secco; shortly put "fresco," meaning the painting on walls when the plaster was wet; "secco," the painting when it was dry. In fresco painting no vehicle was used but water; in secco painting a tempera was used composed of white and yolk of egg. Thus, in Cennino Cennini's Treatise on Painting, written in 1437,[23] he says:—"Two sorts are good, but one is better than the other. The first tempera consists in the white and yolk of an egg into which are put some cuttings from the top of a fig-tree; beat them well together, then add some of this tempera, and not in too great quantity, to each of the vases (of colour), as if you were diluting them with water. The second kind of tempera is the yolk of the egg only, and you must know that this tempera is of universal application on walls, on pictures, and in fresco, and you cannot use too much of it, but it would be wise to take a middle course."

It is to be noted that in his instructions for colouring in fresco, Cennini is very particular to state several times that no vehicle is to be used except water. All frescoes at this time were re-touched in secco, with temperas such as above described; the fresco seems to have been somewhat similar to the first painting in oil, and to have received all its more minute details from the subsequent work in secco. This was almost inevitably the case, as from the haste with which large spaces of the wall had to be covered, there could hardly be time to put in much detail, besides, many of the colours employed could not be used in fresco,[24] though all were used to finish works originally painted in fresco. Secco had an especial province of its own; all pictures, as distinguished from wall paintings, being executed in it. It must be remembered that in the time of Giotto the use of canvas was not yet introduced, and all small designs were painted upon linen cloths, stretched tightly over the surface of a smooth panel, and covered with coats of plaster carefully trimmed;[25] the next step in the preparation of the ground was to substitute parchment stretched over wood for the prepared linen.

It must be noticed that from the time of Cennini to that of Raphael, the practice of completing the fresco in secco grew gradually to be considered as a mark of an inferior artist, though it was never wholly discontinued (according to Mrs. Merrifield's treatise), except by a few "very expert artists, formed chiefly in the school of the Carracci." It is perhaps not always borne in mind by those unacquainted with painting, that the range of colouring in fresco is strictly limited; no colours being employed in it by the early Italians except such as were natural, and nearly all the more brilliant colours are artificial, such, for instance, as lake, vermilion, azure. The blues were more fugitive than any other hues, and in many cases have wholly disappeared, turned green or black, or flaked off from the surface of the walls.

Thus it will be clearly understood that the difference between painting in fresco and painting in secco, or (as it is more commonly called) in distemper, lies in two things, the kind of vehicle employed—water in the first, and glue of some sort (chiefly of egg) in the second method; and in the nature of the colours used, the first being restricted to tints comparatively simple and elementary, the second able to make use of the most elaborate colours obtainable. The first method is eminently suited to the expression of great thoughts in simple language, the second is more adapted to give pleasure, from the exquisiteness of the colours employed, and the skill with which the details are elaborated. The latter is the painting of the studio; the former the painting of the church, the palace, or the market-place. I do not think this difference is sufficiently understood in the present day; it does not appear as if painters had grasped the fact that the greatest strength of fresco lay in its emancipation from all the necessities of minute detail and careful elaboration; a freedom gained by the nature of the material. It is not that in itself this freedom is a good thing, but that it affords the artist a means of expression which he can hardly gain through the medium of painting in oil. In much the same way as a modern dining-room, however perfect in its decoration and gorgeous in its upholstery, can never give us the same effect as the rough pillars of some ruined temple; so does the comparative rough sublimity of fresco afford to a true artist a means of expressing great thoughts and lofty ideas in a comparatively facile manner. For it must be remembered he has not only spaces to decorate of a size commensurate with his subject, be it ever so important, but he has hardly to do more than to express his great thought clearly, and all small details are lost in the splendour of his conception. This is the real power of size in painting; a large picture, if it be not finished with the care of a small one, needs to be a representation of some thought which gains in grandeur from the size of its canvas; there can be no justification for covering ten feet square with the representation of an incident of no particular importance, or a scene of no particular beauty; for with every added foot of space which the artist takes up, he really makes an added claim to importance, and a subject which might have been of sufficient interest to have justified a painting on a minute scale, does but betray its insignificance when delineated on a large one. The whole of art being but the nicest possible adaptation of means to ends, it rightly shocks and repels us when we find an artist wilfully violating these conditions, and, in order to appear of greater importance in our eyes, making what might be a tolerable molehill, into a very indifferent mountain. This was very clearly seen by the old Italian masters, who almost invariably chose fresco as the medium for their most important works, assigning to oil painting a lower province.

In connection with this subject the following quotation of Michelangelo's opinion may be interesting:—"Quand il fut question de peindre dans la Chapelle Sextine, le frÈre Sebastiano, peintre VÉnitienne, conseiller de le Pape, de forcer Michel Ange À le faire À l'huile, et la mur fut prÉparÉ À cet effet. Le grand homme arrive, et fait degrader cet apprÊt, disait fiÈrement que la peinture À l'huile n'Était bonne que pour les dames, les personnes lentes, et qui se pique l'adresse, tels que le frÈre Sebastiano; et l'ouvrage fut fait À fresque, parce que À genre de peinture mÉprise cette attention À manoeuvre; vain merite qui est perdu pour elle. La touche disparait dans l'enduit qui la dÉvore, elle n'occupe pas l'Âme du grand artiste, qui alors tout entiÈre aux caractÈres, aux formes, aux expressions, et À la saillie des corps. Son goÛt ne se manifeste pas sans science, sa main ne s'occupe que d'expÉrience, et il se livre tout entier À cette tÂche difficile—la seule digne de lui. S'il la remplie, la spectateur est transportÉ, et comme l'auteur, il va cherche rien au-delÀ."[26]

We cannot stay to define the limits, within which it seems to us that this is a correct expression of the merits of fresco, but that it is in the main true is indisputable, and it is impossible to tell the good effect which might be produced upon the art of the present day, by encouraging our young painters to work in fresco, simply requiring of them that they should have something to say, and say it clearly. No theories as to the production of a great school of painting, will, I think, be able to map out a better means of attaining good art, than this simple one of making clear expression of a great subject the first object. Curiously enough, the only English artist who seems thoroughly to have understood the great scope of fresco painting was Fuseli, and in his lectures at the Royal Academy may be found a clear and enthusiastic exposition of this method.