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.
" 'Je vois bien," Datnun dit, 'que vous voulez que le peintre ne laisse rien echapper de lout ce qui est de plus avantageux dans son art.' " - Du Pile: Dial. p. 9.
Hitherto we have treated of colour only, which is the universal quality of pigments, and of its relations, physical causes, and changes; there remain, therefore, for discussion the more material properties, upon which depend the various uses, excellences, and defects of pigments.
The general attributes of a perfect pigment are beauty of colour, comprehending pureness and richness, brilliancy and intensity, delicacy and depth, - truth of hue, - transparency or opacity, well-working, crispness, setting-up or keeping its place, and desiccation or drying well; to all which must be superadded durability when used, a quality to which the health and vitality of a picture belong, and is so essential, that all the others put together without it are of no esteem with the artist who merits reputation: we have, therefore, given it a previous distinct consideration.
No pigment possesses all these qualifications in perfection, for some are naturally at variance or opposed; nor is there any pigment that cannot boast excellence in one or more of them. Beauty, delicacy, purity, and brilliancy, are commonly allied in the same pigment, as are also depth, richness, and intensity in the beauty of others; and some pigments possess all these in considerable degree: yet delicacy and depth in the beauty of colours are at variance in the production of all pigments, so that perfect success in producing the one is attended with some degree of failure in the other, and when they are united it is with some sacrifice of both; - they are the male and female in beauty of colour; the principle is universal, and the Hercules, Venus, and Apollo, are illustrations of it in sculpture. Hence the judicious artist pur* veys for his palette at least two pigments of each colour, one eminent for delicate beauty, the other for richness and depth. Of the importance of beauty in colours and pigments there can be no dispute, since it is equally a maxim in colouring as of sounds in music, that if individual colours or sounds be disagreeable to the eye or ear, no combination of them can be pleasing either in melody or harmony, succession or conjunction.
Truth of hue is a relative quality in all colours, except the extreme primaries, in the relations of which blue, being of nearest affinity to black or shade, has properly hut one other relation, in which it inclines to red, and becomes a purple blue; it is, therefore, a faulty or false hue when, inclining to yellow, it becomes of a green hue: but red, which is of equal affinity to light and shade, has two relations, by one of which it inclines to blue, and becomes a purple-red or crimson; and by the other it inclines to yellow, and becomes an orange-red or scarlet, neither of which are individually false or discordant; yet yellow, which is of nearest affinity to white or light, has strictly but one true relation by which it inclines to red, and becomes a warm yellow, for by uniting with blue it becomes a defective green-yellow. Thus greenness is inimical to truth of hue in these primaries, agreeably to the law or regulation by which green is as naturally adapted to contrast as it is inept to compound with colours in general. The other secondary and tertiary colours, having all duplex relations, may incline without default to either of their relatives.
Transparency is an essential property of all glazing colours, and adds greatly to the value of dark or shading colours; indeed it is the prime quality upon which depth and darkness depend, as whiteness and light do upon opacity or reflecting power. Opacity is, therefore, the antagonist of transparency, and qualifies pigments to cover in dead-colouring or solid painting, and to combine with transparent pigments in forming tints; and hence also semitransparent pigments are qualified in a mean degree both for dead colouring and finishing. As excellences, therefore, transparency and opacity are relative only - the first being indispensable to shade in all its gradations, as the latter is to light. With regard to transparent and opaque pigments generally, it is worthy of attention in the practice of the oil painter, that the best effects of the former are produced when they are employed with a resinous varnish; as opaque pigments are best employed in oil, and the two become united with best effect in these united vehicles. The natural and artificial powers, or depth and brilliancy, of every colour lie within the extremes of black and white; it follows, therefore, that the most powerful effects of transparent colours are to be produced by glazing them over black and white: as, however, few transparent pigments have sufficient body or tingeing power for this, it is often necessary to glaze them over tints or deep opaque colours of the required hues. There is a charm in transparent colours which frequently leads to an undue use thereof in glazing; but glazing, scumbling, and their combined process must be used with discretion, according to the objects and effects of a picture.
The effects of the first is of a gay character, and is more powerfully effective when contrasted by the sadness of dry scumbling and solid painting. Glazed colours are rendered much more resplendent by a rough or broken surface of light colouring beneath, whether such surface be produced by the coarse texture of the pigment employed, the palette knife or the pencil.
Working well is a quality which depends principally upon fineness of texture and what is called body in colours; yet every pigment has its peculiarities in respect to working both in water and oil, and these must become matters of every artist's special experience; and some of the best pigments are most difficult of management, while some ineligible pigments are rich in body and free in working; - yet accidental circumstances may influence all pigments in these respects, according to the artist's particular mode of operation and his vehicle, upon the affinities of pigments with which depend also their general faculties of working, such as keeping their place, crispness or setting-up, and drying well; but these latter and other qualities and accidents of pigments have little of a general nature, and will be particularly considered in treating of the individual characters of pigments: it may, however, be remarked, that crispness, setting-up, and keeping their place and form in which they are applied, are contrary to the nature of many pigments, and depend in painting with them upon a gelatinous texture of their vehicle; - thus mastic and other resinous varnishes give this texture to oils which have been rendered drying by the acetate or sugar of lead; - simple water also, albumen, and animal jelly made of glue or isinglass, give the same property to oils and colours: bees'-wax has the same effect in pure oils. White lac varnish, and other spirit varnishes, rubbed into the colours on the palette, enable them also to keep their place very effectually in most instances. This is important also, because glazing cannot be performed unless it be with a vehicle which keeps its place, or with colours which give this property to the vehicle, as some lakes and transparent colours do.