At length they chanced to meet upon the way SPENSER, FAIRIE QUEEN, Canto I. 29. Most of the black pigments in use are produced by charring, and owe their colour to the carbon they contain: such are Ivory and Bone blacks, Lamp black, Blue black, Frankfort black, &c. The three first are most in use, and vary according to their modes of preparation or burning; yet fine Frankfort black, though principally confined to the use of the engraver and printer, is often preferable to the others. Native or mineral blacks are heavy and opaque, but dry well. Some of the old masters are said to have employed a black lake of great beauty, and all coloured lakes calcined in close vessels become such; or perhaps they employed the sediment of the dyer's. vat, which Pliny informs us was used by the antients, and which nevertheless could not have been a durable nor eligible pigment, more especially in distemper or fresco. It is probable also that this black lake may have been a synthetic black, composed of primary or secondary transparent colours, or by addition of coloured lakes to other blacks as the case might require. Prussian blue and burnt lake afford a powerful black; and compound blacks, in which transparent pigments are employed, will generally go deeper and harmonize better with other colours than any original black pigment alone: hence lakes and deep blues, added to the common blacks, greatly increase their clearness and intensity; and ultramarine has evidently been employed in mixture and glazing of the fine blacks of some old pictures. In this view, black altogether compounded of ultramarine, cobalt blue, or Prussian blue, with red and yellow lakes, subordinated according to the powers of the pigments used, will afford the most powerful and transparent blacks; but they dry badly in oil, as is indeed the case also of most other blacks. Black pigments are innumerable: the following are however the principal, all of which are permanent colours : I. IVORY BLACK and Bone Black are ivory and bone charred to blackness by strong heat in closed vessels. These pigments vary principally through want of care or skill in preparing them when well made, they are fine neutral blacks, perfectly durable and eligible both for oil and water painting; but when insufficiently burnt they are brown, and dry badly; and when too much burnt, they are cineritious, opaque, and faint in colour. Of the two, ivory affords the best pigment; but bone black is commonly used, and immense quantities are consumed with sulphuric acid in manufacturing of shoe-blacking. II. LAMP-BLACK, or Lamblack, is a smoke black, being the soot of resinous woods, obtained in the manufacturing of tar and turpentine. It is a pure carbonaceous substance of a fine texture, intensely black, and perfectly durable, but dries badly in oil. This pigment may be prepared extemporaneously for water painting by holding a plate over the flame of a lamp or candle, and adding gum-water to the colour: the nearer the plate is held to the wick of the lamp, the more abundant and warm will be the hue of the black obtained; at a greater distance it will be more effectually charred and blacker. This is a good substitute for Indian ink, the colouring basis of which appears to be lamp-black. III. FRANKFORT BLACK is said to be made of the lees of wine from which the tartar has been washed, by burning, in the manner of ivory black. Similar blacks are prepared of vine twigs and tendrils, which contain tartar; also from peach-stones, &c. whence Almond black; and the Indians. employ for the same purpose the shell of the cocoa-nut: and inferior Frankfort black is merely the levigated charcoal of woods, of which the hardest, such as the bor and ebony, afford the best. Fine Frankfort black, though almost confined to copper-plate printing, is one of the best black pigments we possess, being of a fine neutral colour, next in intensity to lamp black, and more powerful than that of ivory. Strong light has the effect of deepening its colour; yet the blacks employed in the printing of engravings have proved of very variable durability. IV. BLUE BLACK is also a well-burnt and levigated charcoal, of a cool neutral colour, and not differing in other respects from the common Frankfort black above mentioned. Blue black was formerly much employed in painting, and, in common with all carbonaceous blacks, has, when duly mixed with white, a preserving influence upon that colour in two respects, which it owes, chemically, to the bleaching power of carbon, and, chroma tically, to the neutralizing and contrasting power of black with white. It would be well also for the art if carbon had a like power upon the colour of oils; but of this it is deficient; and although chlorine destroys their colour temporarily, they re-acquire it at no very distant period. V. SPANISH BLACK is a soft black, prepared by burning cork in the manner of Frankfort and ivory blacks; and it differs not essentially from the former, except in being of a lighter and softer texture. It is subject to the variation of the above charred blacks, and eligible for the same uses. VI. PURPLE BLACK is a preparation of madder of a deep purple hue approaching black: its tints with white lead are of a purple colour. It is very transparent and powerful, glazes and dries well in oil, and is a durable and eligible pigment, more properly belonging perhaps to the semineutral class of marrone. VII. MINERAL BLACK is a native impure oxide of carbon, of a soft texture, found in Devonshire. It is blacker than plumbago, and free from its metallic lustre,-is of a neutral colour, greyer and more opaque than ivory black,-forms pure neutral tints, and being perfectly durable, and drying well in oil, it is valuable in dead colouring on account of its solid body, as a preparation for black and deep colours before glazing. It would also be the most durable and best possible black for frescos. VIII. BLACK OCHRE is a variety of the above, combined with iron and alluvial clay. It is found in most countries, and should be washed and exposed to the atmosphere before it is used. Sea-coal, and innumerable black mineral substances have been and may be employed as succedanea for the more perfect blacks, when the latter are not procurable, which rarely happens. IX. BLACK CHALK is an indurated black clay, of the texture of white chalk, and is naturally allied to the two preceding articles. Its principal use is for cutting into the crayons, which are employed in sketching and drawing. Fine specimens have been found near Bantry in Ireland, and in Wales, but the Italian has the best reputation. Crayons for these uses are also prepared artificially, which are deeper in colour and free from grit. Charcoal of wood is also cut into crayons for the same purpose. X. INDIAN INK. The pigment well known under this name is principally brought to us from China in oblong cakes, of a musky scent, ready prepared for painting in water; in which use it is so well known, and so generally employed, as hardly to require naming. It varies, however, considerably in colour and quality, and is sometimes, properly, called China ink. Various accounts are given by authors of the mode of preparing this pigment, the principal substance or colouring matter of which is a smoke black, having all the properties of our lamp-black, and the variety of its hues and texture seems wholly to depend upon the degree of burning and levigating it receives. XI. BLACK LEAD, Plumbago, or Graphite, is a native carburet of iron or oxide of carbon, found in many countries, but nowhere more abundantly nor so fine in quality as at Borrodale in Cumberland, where there are mines of it, from which the best is obtained, and consumed in large quantity in the formation of crayons and the black-lead pencils of the shops, which are in universal use in writing, sketching, designing, and drawing-for which the facility with which it may be rubbed out by Indian rubber, caoutchouc, or gum-elastic, and the crumb of bread, admirably adapts it.* Although not acknowledged as a pigment, its powers in this respect claim a place for it, at least among water-colours; in which way, levigated in gumwater in the ordinary manner, it may be used effectually with rapidity and freedom in the shading and finishing of pencil drawings, &c., and as a substitute therein for Indian ink. Even in oil it may be useful occasionally, as it possesses remarkably the property of covering, forms grey tints, dries quickly, injures no colour chemically, and endures for ever. Drawings, &c. in pencil are sometimes required to be fixed. This is best and most easily done with water-starch, prepared in the manner of the laundress, of such strength as just to form a jelly when cold, which may be then applied with a broad camel's-hair brush, as in varnishing. The same may be done with thin, cold isinglass size, or rice-water. CHAP. XXII. TABLES OF PIGMENTS. As there are circumstances under which some pigments may very properly and safely be used, which under others might prove injurious or destructive to the work, the following Lists or Tables are subjoined, in which they are classed according to various general properties, as guides to a judicious selection. These Tables are the results of direct experiments and observation, and are composed, without regard to the common reputation or variable character of pigments, according to the real merits of the various specimens. tried. The powers of pigments therein adverted to might have been denoted by numbers; but since there is no exact and constant agreement in different specimens of like pigments, nor relatively among different pigments, it would have been an affectation of accuracy without utility: add to which, the properties and effects of pigments are much influenced by adventitious circumstances, and are sometimes varied or altogether changed by the grounds on which pigments are used; by the vehicles in which they are used; by the siccatives and colours with which they are used; and by the varnishes by which they are covered. These Tables are therefore offered only as approximations to the true characters of pigments, (some of which, for the above reasons, are liable to be disputed,) and as general guides to right practice. They render it also apparent as a general conclusion, that the majority of pigments have a mediocrity of qualification balancing their excellences with their defects. and that the number of good and eligible pigments overbalances those which ought in general to be rejected. |