Hodson – Dougall 1805

Thomas Hodson – John Dougall, The Cabinet of the Arts; Being a New and Universal Drawing Book, Forming a Complete System of Drawing, Painting in all its Branches, Etching, Engraving, Perspective, Projection, & Surveying: with all their various & appendant parts. Containing the Whole Theory and Practice of the Fine Arts in General, From the first Elements to the most finished Principles…, London [Thomas Ostell] 1805.

BOOK IV.

OF PAINTING.

. . .

pp. 271–273

SECTION V.

PAINTING IN FRESCO.

PAINTING in fresco is considered as the most antient, the most speedily executed, and the most durable branch of the art, as well as the most suitable for ornamenting great buildings. From the fragments that have come down to our times, it appears that the Romans worked much in this way; and travellers in Egypt tell us of colossal figures, painted on walls of palaces and temples in that country, eighty feet high. By the description given of the ground of these pictures, and of the way in which the colours seem to have been employed, they must have been done in what is now called fresco. The durability of this kind of painting is proved by the existence of these paintings; for no other sort could so long have resisted the effects of the weather, or the rude attacks of the barbarous inhabitants amongst whom they are found. Authors are divided as to the best climate and situation for paintings in this way: some asserting, that at Paris, for example, such works stand longer than in the south of France or Italy, on account of the lower degree of heat: this is as positively denied by others, who affirm that fresco paintings are longer preserved in dry and warm climates than in those that are moist and cold. But other circumstances ought to be taken into consideration, such as the effects of a fire in the apartment where the paintings are; and of the frost, when allowed to penetrate to them: for frost, as is well known, will burst stones, and affect the internal parts of the bodies on which the paintings are performed, as well as the substances of which they consist. The choice of place where fresco is to be executed is therefore of the highest importance. In a country where frosts are little felt, the best situation seems to be a northern exposure, but in cold climates a western exposure promises to be more favourable; as were the painting exposed to the sun’s rays, immediately or soon after the frost, the effect would be very pernicious. Moisture, however, does not appear to be so dangerous to works in fresco as has been supposed, of which we have instances in the antient paintings rescued from damp places where they had lain covered for many ages, under heaps of earth, and yet have retained their colours in great perfection: and many of which, as these discovered in the ruins of Herculaneum, overwhelmed by Mount Vesuvius, have lost their colour soon after they had been exposed to and dried by the external air. Again, the mortar of which the original ground of these works is composed, resists the effects of even our rainy climates: instances are frequently met with of the mortar being more tenacious and durable than the stones or bricks it was employed to cement together.

In executing fresco paintings, next to the choice of a situation, the choice of the necessary materials is of the greatest importance; as its durability depends chiefly on the ground on which it is executed. For it will readily be perceived, that minuteness of detail in the forms, an extensive mixture and gradation of tints, delicacy of touch, can make no part of the merits of this kind of painting. It cannot support a narrow examination like a work in oil, because, from its nature, it is liable to a hard and rough appearance, which would offend when brought near the eye. Fresco paintings are chiefly employed in palaces, temples, and other public edifices; and in such situations it is preferable to any other, from the size, the boldness of design, and the freshness of colouring of the figures. They have, in particular, an admirable effect in the roof of a dome, and transport the imagination far beyond the limits of the building.

Fresco painting is usually executed in the following manner: – It is necessary to apply two layers for the ground work to the wall: when this is a brick wall, these layers are easily applied; but when it is of stone, holes are made in it, to receive large nails or wooden pegs to hold fast the first coating of the ground. The first layer is made of good lime and a cement composed of pounded brick, or of what is still better, river sand, which makes a surface more rough and uneven than the pounded brick, and therefore better suited for retaining the second layer. The first layer ought to be perfectly dry before the second, on which the painting is to be done, be applied. The second layer consists of lime slaked in the open air, and left exposed for a year to the weather, mixed with river sand, moderately fine, and of an equal grain. This is applied with a trowel to the first layer, whose surface has been previously wetted, to make the two unite, and requires great skill and dexterity in the artist, that the last surface may be made perfectly even and regular. A fine polish is given to this second layer by applying a sheet of smooth paper to it, and again going over the paper with the trowel, to remove even the smallest inequalities which would give a false appearance to what is to be painted on them, according to the position and distance of the spectator. The artist employed on this preparatory work, is to lay only so much ground as the painter can execute in a day; as this kind of painting can only be performed when the ground is fresh laid on and smoothed. When the layers are thus prepared the painter begins his work: but as he must work rapidly, and as there is no time to retouch any of the strokes, he must have by him large cartoons, on which are drawn, with correctness, and in full size, the figures to be painted; that he may have nothing to do but to copy them on the wall. The cartoons are a number of sheets of large strong paper, either single, or several folds pasted together, as may be most suitable to the painter’s purpose. These cartoons are applied to the surface of the wall, and the various outlines, features, &c. are traced on the plaster, by going over the cartoon with a steel point, or merely by pricking small holes through the paper. When in this manner an accurate and speedy drawing is obtained, nothing remains but to execute the painting. The colours are laid on while the layer of plaster is moist, and they ought not to be retouched when dry, with other colours mixed with the white of eggs, gum, &c. as has sometimes been practised; as these last are sure to turn black, and none but such as are laid on the moist plaster retain their hues. The colours commonly used are a white, made of lime slaked a long while before it is employed in the painting, and the dust of white marble; ochres, both red and yellow; verditer, lapis lazuli, smalt, black chalk, &c. all which substances are simply ground down and worked up with water; and most of them grow brighter as the plaster dries. The brushes and pencils used are long and soft, that they may not scratch or raise the painting. The colours ought to be full, and flowing freely from the tools; and great care must be taken that the design be perfect at first, since no alteration can be made after the work is dry, nor any colour

The colours employed in Fresco painting are such as are extracted from different earths, or which have passed through the fire. Some colours require to be used with great caution, such as enamel blue, cinnabar, and white marble dust. When enamel blue is used, it must be applied instantaneously, and while the lime is very moist, otherwise it will not incorporate with the plaster; and should it be necessary to retouch the work with this colour, it must be done an hour or more after the first application, that its brilliancy may be augmented. White marble dust is apt to turn black, unless it be mixed up with a proper quantity of white lime. Cinnabar, although one of the most splendid colours, almost entirely loses its brilliancy when mixed with lime: it may, however, be employed in situations not exposed to the air, by using certain precautions in the preparation: for instance, the cinnabar, the purer the better, must be reduced to powder, put into an earthen vessel, and covered three or four different times with lime water. By this preparation the cinnabar is in some degree combined with the lime water, and so rendered fit for use in fresco painting. One of the most useful colours for giving the proper tone and gradation of tints is the white of lime, prepared by mixing lime which has been for a long time slaked, with pure water: this deposites a sediment, which, when the water is poured off, is the white of lime. Another sort of white may be used, that is, the white of egg shells; being prepared in this manner, a quantity of shells of eggs are to be pounded and boiled in water, together with some quick lime; they are then strained off, and washed repeatedly with rain water. The shells are again pounded, and washed until the water come off pure and clear. Being in this way reduced to powder, the powder is ground down in water, and formed into small pieces, to be dried in the sun. All sorts of ochres furnish excellent colours for fresco painting, and a great variety of shades and tints. Naples yellow is sometimes used, but it does not stand when much exposed to the air. Good black colours may be obtained from charcoal, peach stones, and vine twigs; that extracted from bones is of no use at all. Roman vitriol, commonly called burnt vitriol, ground down in spirits of wine, withstands the effects of the air extremely well, when employed in lime. A red colour is also extracted from the same preparation, which is very useful for preparing the ground to receive cinnabar; and draperies done with these two colours, have a peculiar brilliancy of hue, rivalling paintings in oil. Ultramarine is a very steady colour, not only free from any tendency to change itself, but communicating the same property to other colours with which it is mixed.

All these colours are prepared by mixing and grinding them in water, and arranging them so as to form the several tints to be employed in the work: these are then put into pots, and the whole number of colours and tints placed in readiness for use. As all the tints, excepting burnt ochre, violet, red, and blacks of all kinds, are apt to become light and clear, the artist should have a piece of dry new brick or tile, on which to try his colours, for the water is soon absorbed by the brick, and their degree of colour may be seen before it is applied to the painting itself.