It is also necessary to have a small phial of the solu tion of gum Arabic, which is to be added to the colours, as may be required, particularly where it is desirable to give great depth of tone to the picture.
The chief quality in a hair pencil is, to have great elasticity, and a fine point, without being itself too small. The sable hair pencils are the best sort.
When a miniature picture, by repeated working and touching, has acquired any asperities on its surface, it will be necessary to remove them by the dextrous ap plication of the scraper, and any damage that it may have sustained by this process, is easily repaired with the hair pencil, and a little colour. The scraper is also of great use in obliterating small touches, which it would be inconvenient to wash off with water, but if the altera tion required is extensive, it is preferable to wash the part with water and hair pencil.
In the execution of a miniature, there are three dif ferent modes of laying on the colours, namely, by flat washes, by hatching, and by stippling. The first term sufficiently explains itself, and by this process the greater pall of the miniature ought to he executed. Ilatehing is that method by which lines are made to cross each other in every direction, in the manner of a stroke en graving ; and stip/iling consists of dots of greater or less size and closeness, according to the effect intended. The hatching and stippling are chiefly to be employ ed in the more delicate parts of the picture, where much variety and richness of colour are to he given ; but they are to be introduced with much caution, so as not so de tract from the smoothness or other qualities of surface which propriety may suggest.
With regard to the degree of finishing, which it may be proper to bestow on works of this kind, no rule can be given ; and the example of many eminent artists of the British school, sufficiently shews, that with judi cious management, guided by sound taste, all the pur poses of art may be attained, either with a light and de licate, or a more elaborate style of execution. Upon the whole, we are rather inclined to give the preference to the light, airy, and tasteful style, as exemplified in the works of Mr. Cosway, and Mr. Antony Stewart, of London, which we conceive more suitable to the gay character of miniature painting. The works of Mr. G. Sanders, Mr. A. Robertson, of London, Mr. W. J. Thomson, and Mr. Nicholson, of Edinburgh, afford a striking illustration of the power and brilliancy of co lour, and strength of chiar'oscuro, of which this de partment of art is susceptible.
As water colours are liable to fade by exposure to light, they ought to be covered with a silk curtain, if they are not secured in a cabinet, which is the most proper place for works of this description, particularly miniatures, where they may be preserved for any length of time. A remarkable proof of this is given by the works of Cooper, an eminent English miniature painter, in the time of King Charles the First ; those specimens which have been preserved in cabinets have retained all the freshness of colouring for which he was so much celebrated, while those that have been expos ed to light have lost all their force.
When a miniature is finished, it is covered with a con vex glass, to which it is fixed all round the edge with goldbeater's skin, and thus it may be preserved from injury for any length of time.
In choosing the attitude, the good sense of the artist will naturally direct him to adopt that which will be most agreeable, and most characteristic of his model; and the same principle will regulate the effect of colour, and light and shadow, according as the subject is gay, animated, or grave ; and this will be much influenced by the proportion which the light bears to the shadow, and the manner in which they are introduced, as well as by the quantity of warm or cold colour which may be allowed to predominate. Thus the effect will be gay, when the white, delicate yellows, orange, and the other light tints prevail ; it will be grave or solemn, when black, blue, and neutral greys form the basis of this effect.
Miniatures on vellum or paper, are executed in the same way as all other water-colour drawings, and as these substances admit of repeated washes over each other, and of blending them together without any risk of washing off the first layers of colour, the processes of hatching and stippling are not so indispensable, although, when judiciously managed, they contribute greatly to the richness of the effect. The only prepa ration which the paper or vellum requires, is a simple wash of the weak solution of ox-gall alteady mention ed, which is of great importance in making the colours work sweetly. Whether vellum or paper be used, in subjects of so much delicacy as portraits of the size in which miniatures are executed, it is obvious that that which has the smoothest surface will be the most proper. What is called Bristol card, affords the best surface, and most agreeable ground ; it is usually of considerable thickness, and is rendered extremely smooth, by means of hot-pressing.