Chapter XIII: Miscellaneous Processes (2)

1. _The Cartoon._ Since the artist cannot without injury retouch a fresco painting, it is necessary that every part of the design be decided on by preparatory sketches finished of the full size, from which the fresco may be transferred, by tracing to the wall. When the painting is very large, the whole composition of the full size is sometimes divided into two or more cartoons.

In the preparation of a cartoon, a strong cloth is stretched on a frame, as if to be prepared for painting; paper is then firmly glued on the cloth. When this is dry, a second layer of paper is attached by glue. The edges of the separate sheets, where they overlap, are scraped, so as to preserve an even surface. The surface is then prepared for drawing with size and alum.[7] The drawing is made with charcoal, and when finished is fixed by wetting the cloth at the back with cold water, and then steaming the drawing in front. The steaming is performed with a tea-kettle with two or three spouts, kept boiling by the flame of a spirit lamp; by this means the charcoal is incorporated with the melted glue, and a solid surface like that of a picture is produced.

From this finished drawing the outline is traced on oiled paper. As much of this working outline as can be finished in one painting is then nailed to the wet wall, and the forms are again traced with a sharp point, whereby an indented outline is produced on the soft plaster. According to another method, the paper to be applied to the wall is placed behind and in close contact with the finished cartoon; the outlines of the latter are then pricked, and a similar pricked outline is thus produced on the paper behind. This pricked paper is then made the working drawing: it is fastened to the wall, and dusted with a little bag filled with black or red dust; this leaves a dotted outline on the wall. This method is sometimes adopted for small works, and the advantage of it is that it leaves the surface of the plaster undisturbed. The first mode is, however, generally preferred; since it insures the best and most decided outline, and preserves the finished cartoon uninjured.

Cartoons prepared for fresco may be seen in the National Gallery: those at the head of the staircase are by Agostino Caracci. In one of these (the Triumph of Galatea) the pricked outline is very apparent; as also in the fragment of the Cartoon by Raphael, (the Murder of the Innocents,) also in the National Gallery. In many celebrated Italian frescos the indented outline, produced by tracing, is apparent.

In addition to the cartoon it is desirable to have a coloured sketch of the whole composition.

2. _The preparation of the Wall._ The greatest obstacle to the permanence of fresco painting is damp: hence, if the wall to be painted is covered with old mortar, the ingredients of which are unknown, this coat should be entirely removed until the solid brick or stone is laid bare. The rough coat then applied is composed of river-sand and lime, and of such thickness as is generally used in preparing the walls of dwelling-houses. The surface of this coat should be rough, but not uneven. Thus prepared, the wall should be suffered to become perfectly dry and hard; the longer it remains in this state the safer it will be, especially if the lime used was in the first instance fresh. In that case two or three years should elapse before the process of painting is commenced.

The preparation and seasoning of the lime is one of the essential conditions of fresco painting. At Munich it is made and kept as follows:--A pit is filled with clean burnt limestone, which is slaked, and then stirred continually till it is reduced to an impalpable consistence. The surface having settled to a level, clean river-sand is spread over it to the depth of a foot or more, so as to exclude the air, and, lastly, the whole is covered with earth. It is allowed to remain thus for at least three years before it is used, either for the purposes of painting (lime being the white pigment) or for coating the walls.

The last preparation for painting on the mortar, is as follows:--The surface is wetted with pure water, till it ceases to absorb. A thin coat of plaster is then spread over that portion only which is to be painted: the surface of this coat should be moderately rough. As soon as it begins to set (_i. e._, in about ten minutes or so, according to the temperature) a second thin coat is laid on, and the surfaces are smoothed with a wooden trowel. Some painters like to work on a perfectly smooth surface, in which case the last coat is polished by applying a piece of paper on the surface, and passing the trowel over it. When a small amount of roughness is required, a dry brush, or a piece of beaver nap attached to the trowel, is passed over the plaster in all directions.

3. _The process of Painting._ The wall being properly prepared, the outline of the figures is to be traced with a sharp point on the plaster, as before described. The artist commences his work when the surface is in such a state that it will barely receive the impression of the finger, and not so wet as to allow the colours to run or to be liable to be stirred up by the brush. If the wall has been previously well wetted, it will in general not dry too rapidly; but if in warm weather the surface becomes too hard to imbibe the colour properly, a small quantity of water is from time to time sprinkled over the surface.

The colours being ground fine in water, and the most useful tints abundantly supplied, they are arranged in pots or basins, and several palettes with raised edges are ready at hand to work from. A few pieces of tile or some absorbent material are provided to prove the tints upon, because all colours ground in water become much lighter when dry than they appear when wet. The brick absorbs the water, and leaves the colour nearly in the state in which it will appear upon the wall.

The first tints that are applied sink in and have a faint appearance; it is therefore necessary to go over the work several times before the full effect is produced: but after some time the last edition of colour will not unite with that already applied unless the part be again wetted.

At the close of a day’s work, any portion of the prepared plaster which remains over and above the finished part is to be cut away, care being taken to make the divisions at a part where drapery, or some object or its outline, forms a boundary, for if this be not attended to, the work will appear patchy. The next day, in preparing a new surface, the edges of the previously painted portion must be carefully wetted so as to ensure a perfect junction of all the parts of the painted surface.

At Munich the artists have a contrivance for arresting the drying of the work should they be unable to finish the day’s allotted portion. A piece of fine linen is wetted and spread over the fresh plaster and painting, and pressed to the surface by means of a cushion covered with waxed cloth.

Defects are sometimes remedied by cutting out the objectionable portion, and painting it anew upon a fresh surface of plaster. In the finished fresco, shadows are sometimes deepened, parts are rounded, subdued, or softened by hatching in lines of the colour required, mixed up with vinegar and white of egg. Crayons made of pounded egg-shells are sometimes used to heighten the lights. But all these additional amendments are highly objectionable; they impair the durability of the fresco, and in the open air these retouchings are useless, because the rain washes them away, whereas it has no influence upon frescos painted without retouching.

4. _The Colours and Implements._ The colours employed in fresco painting are few and simple. They consist chiefly of earths and a few metallic oxides variously prepared. No animal and vegetable substances can be used, because the lime would destroy them. The brushes are of hog’s hair, but longer than those used in oil painting. Small pencils of otter hair are also used; no other hair being found to resist the lime. Pure distilled water ought to be employed in all the operations of this art.

Such is the process of fresco painting, the details of which, after the above statement, will be rendered more intelligible by the following abridged account of a visit, by Mr. Andrew Wilson, to the royal palace at Genoa, to see the Signor Pasciano paint a ceiling in fresco:--

The artist had prepared his tints upon a table with a large slate for the top: they consisted of terra vert, smalt, vermilion, yellow ochre, Roman ochre, darker ochre, Venetian red, umber, burnt umber, and black. These colours were all pure, mixed with water only, and rather stiff. He mixed each tint as he wanted it, adding to each from a pot of pure lime, or from one containing a very pale flesh tint. A lump of umber served to try his colours on. He used a resting-stick with cotton on the top to prevent injury to the prepared wall, or _intonaco_, as the Italians call it. The moment this surface would bear touching, the artist began to work upon the figure, the outline of which had just been traced. The head was that of the Virgin. The artist began with a pale tint of yellow round the head for the glory: he then laid in the head and neck with a pale flesh colour, and the masses of drapery round the head and shoulders with a middle tint, and with brown and black in the shadows. He next, with terra vert and white, threw in the cool tints of the face; then with a pale tint of umber and white, modelled in the features, covered with the same tint the part where the hair was to be seen, and also indicated the folds of the white veil. All this time he used the colours as thin as we do in water colours; he touched the intonaco with great tenderness, and allowed ten minutes to elapse before touching the same spot a second time. He now brought his coloured study, which stood on an easel near him, and began to model the features, and to throw in the shades with greater accuracy. He put colour in the cheeks, and put in the mouth slightly, then shaded the hair and drapery, deepening always with the same colours, which became darker and darker every time they were applied, as would be the case on paper for instance. Having worked for half an hour, he made a halt for ten minutes, during which time he occupied himself in mixing darker tints, and then began finishing, loading the lights, and using the colours much stiffer, and putting down his touches with precision and firmness: he softened with a brush with a little water in it. Another rest of ten minutes; but by this time he had nearly finished the head and shoulders of his figure, which being uniformly wet, looked exactly like a picture in oil, and the colours seemed blended with equal facility. Referring again to the oil study, he put in some few light touches in the hair, again heightened generally in the lights, touched too into the darks, threw a little white into the yellow round the head, and this portion of his composition was finished, all in about an hour and a half. This was rapid work, but it will be noticed that the artist rested four times, so as to allow the wet to be sufficiently absorbed into the wall to allow him to repass over his work. He now required an addition to the intonaco; the tracing was again lifted up to the ceiling, and the space to be covered being marked by the painter, the process was repeated, and the body and arms of the figure were finished.

On the occasion of a second visit, Mr. Wilson remarked that the artist had cut away from his tracing or cartoon those parts which he had finished upon the ceiling: that the tracing was in fact cut into several portions, but always carefully divided by the outline of figures, clouds, or other objects. These pieces are nailed to the plaster, so as to fold inwards or outward for the convenience of tracing the outlines. The artist was now about to proceed with a group of figures. Having gone over the outline carefully with a steel point, he waited till the intonaco became a little harder, and in the mean time mixed up a few tints; he then commenced with a large brush, and went over the whole of the flesh; he next worked with a tint which served for the general mass of shadow, for the hair, and a slight marking out of the features. He now applied a little colour to the cheeks, mouth, nose, and hands, and all this time he touched as lightly as possible. He then paused for ten minutes, examined his oil study, and watched the absorption of the moisture.

The intonaco would now bear the gentle pressure of his fingers, and with the same large brush, but with water only, he began to soften and unite the colours already laid on. He had not as yet used any tint thicker than a wash of water-colour, and he continued to darken in the shadows without increasing the force or depths of colour. The artist now increased the number of his tints; he made them of a much thicker consistence, and he now began to paint in the lights with a greater body of colour, softening them into the shades with a dry brush, or with one a little wet, as was required. In drying, the water comes to the surface and actually falls off in drops, but this does no harm, although, as Mr. Wilson remarks, it sometimes looks alarming.

The effect of fresco painting is described as being exceedingly beautiful. It does not require for the production of its general effect those particular and concealed lights which the shining surface of an oil-painting renders necessary. Fresco is seen entire in any situation and by any light, even by artificial light, which perhaps shows it best. Mr. Severn was much struck by the increased beauty and power of the Caracci frescos at Rome by artificial light. Even a dim or diminished light does not destroy their effect.

“It must have been for this reason that Raphael adopted fresco in the Vatican, after he had made experiments in oil; for the rooms are so ill-lighted, that oil pictures could never have been seen at all; and it is surprising to find such fine works in such a place. Three sides of the rooms are illuminated merely by the reflected light from the great wall of the Sistine chapel, yet this beautiful and luminous material of fresco is so brilliant in itself, that the pictures are well seen. Nine of them were painted without a ray of real light, and have always been seen in the same way. I think this is a very important consideration; for as we have but a diminished light at any time, it is most necessary to adopt a manner of painting suited to it, which can be seen at all times.”

Fresco does not seem to be at all understood in this country; it is generally confounded with scene painting; it is a common mistake to suppose that the cartoons of Raphael are the same as his frescos. It is often confounded with distemper painting, which is done on a dry ground, and does not admit of richness of colour.

“This will be clearly understood (writes Mr. Severn) by those who have had the good fortune to see Raphael’s and Guido’s frescos at Rome, which for colour are exquisitely beautiful, and even powerful in all the fascinations of this part of the art, presenting to us still greater varieties than oil painting can pretend to; excelling in all the delicate effects of atmosphere, from the gorgeous daylight, the air of which you seem to breathe in a fresco picture, down to the silvery flitting charm of twilight. In these particulars, it reminds us of English water-colour effects. Then I should mention the magnificence of fresco landscape, and of landscape backgrounds, particularly by Domenichino, in which not only the characters, but the movements of trees, are always rendered in a way which I have rarely seen in oil colours.... Then I must remind you of the grandeur of colour and effect in Michael Angelo’s frescos on the ceiling of the Sistine chapel. What oil could ever have approached such things? When he said ‘that oil painting was only fit for women and children,’ he meant on account of the labour and difficulties of the material compared with fresco. We are assured he performed this gigantic labour in twenty months, without the usual assistance of colour-grinders or plasterers, but alone with his own hand. There are on this ceiling fourteen figures, of at least forty feet in stature, and nearly five hundred figures, the least of which are double the size of life. While we regard this as the most extraordinary example of individual human power, we must consider that it was only in the simplicity and ease of the fresco material that Michael Angelo could have accomplished such a stupendous work. The preparation of oil colours, varnishes, &c., would alone have occupied the twenty months.”

The small cost and great durability of frescos are not the least of their advantages. It was feared that the smoke of London would soon destroy our frescos, but Professor Hess stated that “if frescos were painted in the open air in London, the rain would be the best picture-cleaner.” Indeed, competent authorities agree that pure water and a soft sponge are the best means for cleaning frescos from the effects of smoke. That the change effected by time on the colours is to increase their effect. The great enemy to fresco is a wall constitutionally damp, in which lime in too new a state has been employed, or new timber or imperfectly burnt bricks. The nitre which sometimes accumulates on walls is also very destructive.

Nor are frescos such permanent fixtures as is generally imagined. Some ingenious Italians have succeeded perfectly in removing large frescos from one wall and applying them securely to another. The colours in fresco do not penetrate very deep, and the thin layer of pigment and lime of which the painting consists, may be removed by glueing several layers of calico to the wall: a slight force is then sufficient to detach the painting: it is removed to its new bed, and when firmly attached, the cloths and glue may be removed by warm water.

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We must now leave the Reader in possession of the dwelling-house which we have endeavoured to build for him. If we have not _furnished_ it, or described the modes in which the various articles of furniture are made, it was not because the subject is devoid of interest, far from it; but because we were anxious not to injure the completeness and interest of the preceding details by attempting too much within the limits of this little volume.

FOOTNOTES:

[7] The term Cartoon is derived from _curtone_, the augmentative of _carta_, the Italian for _paper_.

LONDON:
SAVILL AND EDWARDS, PRINTERS,
CHANDOS STREET.

Transcriber’s Notes

In a few cases, obvious errors in punctuation have been fixed.

Page 28: “the standstones of which” changed to “the sandstones of which”

Page 141: “the vessel _e_” changed to “the vessel _c_”

Page 213: “upon the cieling” changed to “upon the ceiling”