This section is from the book "Chromatography; Or, A Treatise On Colours And Pigments, And Of Their Powers In Painting", by George Field. Also available from Amazon: Chromatography, or A Treatise on Colours and Pigments, and of Their Powers in Painting.
The art of painting in fresco is so naturally adapted to the grandeur of historical and patriotic painting, to which it appears to have been first applied, and the zealous attention of eminent artists being at present turned to the revival of this great and free mode of art, we will not withhold the few observations we have made thereon in connexion with colours and colouring, however brief our experience may have been.
It is hardly necessary to inform the reader, that fresco painting is performed with pigments prepared in water, and applied upon the surface of fresh laid plaster of lime and sand, with which walls are covered; and as it is that mode of painting which is least removed in practice from modelling or sculpture, it might not improperly be called plastic painting.
As lime, in an active state, is the common cementing material of the ground and colours employed in fresco, it is obvious that such colours or pigments only can be used therein as remain unchanged by lime. This need not, however, be a universal rule for painting in fresco, since other cementing materials, as strong or stronger than lime, may be employed, which have not the action of lime upon colours - such is calcined gypsum, of which plaster of Paris is a species; which, being neutral sulphates of lime, exceedingly unchangeable, have little or no chemical action upon colours, and would admit even Prussian blue, vegetal lakes, and the most tender colours to be employed thereon, so as greatly to extend the sphere of colouring in fresco, adapted to its various design; which bases merit also the attention of the painter in crayons and distemper.
So far too as regards durability and strength of the ground, the Parker's or Roman cement, now so generally employed in architectural modellings, would afford a new and advantageous ground for painting in fresco; and, as it resists damp and moisture, it is well adapted, with colours properly chosen, to situations in which paintings, executed in other modes of the art, or even in ordinary fresco, would not long endure.
As these materials, and others now in use, were either unknown or unemployed by the antient painters in fresco, their practice was necessarily limited to the pigments enumerated in the preceding Table; but every art demands such a variation in practice as adapts it to circumstances and the age in which it is exercised, without attention to which it may degenerate, or, at best, remain stationary, but cannot advance.
In point of durability, however, both as respects colours and texture, the frescos of the antient Egyptians (if they may be so called) have alone pretensions to the character of almost perpetual incorruptibility; in which respect fresco must have declined, at the same time that painting as an art advanced, even among the Greeks; while many of the earlier works of the moderns, founded on the basis of Grecian art, have nothing to boast of in this respect; and the " Last Judgment" of Michael Angelo, and many great performances, may be adduced as examples thereof; so that, aided by modern chemistry, we may hope, not only the restoration, but improvement of this art.
Although differing exceedingly in their mechanical execution, the modes of fresco, distemper, and crayon painting agree in their chemical relations, so far, therefore, as respects colours and pigments, the foregoing remarks apply to these latter arts. In distemper painting, however, the carbonate of lime, or whitening employed as a basis, is less active than the pure lime of fresco. The vehicles of both modes are the same, and their practice is often combined in the same work: water is their common vehicle; and to give adhesion to the tints and colours in distemper painting, and make them keep their place, they are variously mixed with the size of glue (prepared commonly by dissolving about four ounces of glue in a gallon of water). Too much of the glue disposes the painting to crack and peel from the ground; while, with too little, it is friable and deficient of strength. In some cases the glue may be abated, or altogether dispensed with, by employing plate of Paris diluted and worked into the colours; by which they will acquire the consistency and appearance of oil paints, without destroying their limpidness, or allowing the colours to separate, while they will acquire a good surface, and keep their place in painting with sufficient strength, and without being liable to mildew, - to which animal glue is disposed, and to which milk, and other vehicles recommended in this mode, are also subject.
Of more difficult introduction in these modes of painting is bees'-wax, although it has been employed successfully in each of them, in the encaustic of the antients, etc.; the body colours of the modems; and, with excellent effect, in cray-ons, - first, we believe, by the late Mr. Adam Buck. Wax is a most incorruptible substance, and communicates many of the qualities of oil-painting. Excellent crayons may indeed be made by mixing melted bees'-wax with powerful well-levigated pigments with turpentine or other essential oil. Such compounds when sufficiently cold may be formed into crayons, which are very useful for putting in of spirited touches, or additions, in water-colour drawings; and a new and durable mode of crayon painting might be formed hereon, by employing these crayons of all required tints, and blending them by means of brushes dipped in an essential oil, in which these crayons are soluble: thus combining the pencil and crayon in the same process of painting.
Remarks. - Heraldry, the most arbitrary of the sciences, having no foundation whatever in nature, has nevertheless employed colours with more consistent classification than the more natural and legitimate arts, and being intimately connected with painting in the emblazoning of arms and the illuminating of missals, books, deeds, and treaties; and being also of occasional reference to higher art, a brief notice of heraldic colouring and its symbols may be considered as a useful appendage to a work on colours. The present Table may also serve, by the comparison of colours, jewels, etc. to denote the colours themselves, and identify their names according to natural resemblances.