First. In painting upon the wax by virtue of the whitening, you will not have that conveniency of retouching or altering of any part, and before the colours are fixed, so well, as painting upon the raw and bare canvas will afford you; because the texture and fibres of the cloth being thoroughly invaded by the wax, there remains nothing for water colours to fix or adhere to, capable to retain them; those colours once dry, the slightest touch of a moist pencil will, as it were, attract them, and frequently make and leave a bare spot; so that in attempting to retouch, instead of adding fresh colours, you will fetch off the old ones: for though the rough edged particles of the chalk facilitate to the first colours an adhesion upon the smooth body wax yet, water the vehicle of the colours, being the menstruum of chalk, by discomposing it destroys part of its power and virtue, and renders it incapable to perform the first service a second time.
Secondly. Upon canvas fully imbibed with wax, you can neither use so great a body of colours, nor employ them with such freedom, boldness, or delicacy as you may upon cloth, whose texture is not pre-occupied with wax—the reason is obvious—the one has its pores and interstices filled up with wax; the other’s you must fill up with colours. Cloth, a firm spungy body or substance, in sucking in the water attracts the colours along with it into its pores, and thereby facilitates the firm and delicate strokes; and the colours mixing and adhering to its numberless fibres, will not come off on retouching, before the picture is fixed; you may cherish or leave your work at pleasure without detriment or inconveniency arising from that. Advantages that cloth pre-occupied with wax is incapable of.
Thirdly and lastly. By painting on canvas prepared according to the directions of Art. the first, your works will be more solid and lasting, because the colours will not simply lay upon the surface of the wax, but cloth, wax and colours will make but one individual body.—Thus much on my deviation from Count Caylus’s system, in regard to the preparation of the cloth.
For painting upon walls or plaister where the wax cannot be applied on the back, the Count’s system must be practised; it will succeed well; the rough and gritty grain of the plaister will take and retain a sufficient quantity of colours to insure solidity; the only difference between painting upon cloth and plaister consists in this; painting upon canvas you can finish your picture entirely before you fix it; in painting upon plaister, you must proceed as you do in painting with oil-colours, viz. first, dead colour your subject and fix it, and then paint it over again and finish it, either by virtue of the chalk, or by tempering and employing the colours with some spirit, or oil of turpentine. You may too paint and retouch with crayons.
Upon wood, stone, and metals,—you must proceed as you do upon plaister; but as there is no grain you must procure an artificial one, after your board is waxed, by laying on a ground of any colour mixed with half chalk and fix it[11]; upon this you may paint with water colours or crayons, as sweetly as upon canvas.
To paint upon paper;—you must have a smooth board, or copper-plate of a convenient size, and well waxed; upon this you fasten your paper by the corners and paint upon; the colours dry, present it to the fire, and the wax underneath the paper melting, will soak and penetrate through and fix the colours; this method may be successfully practised with cloth.
There are two more methods remaining to be practised on cloth and paper; but as they make part of the system for painting with crayons, and will be described under that head, I omit to mention them here.
Observations on Article the second.
In grinding the colours upon the stone, and managing them upon the pallette, care should be taken not to use an iron knife, the steel or iron that grinds off, in mixing with the colours spoils their brightness and vivacity; flake-white and white-lead, yellow-oker, lacque and light-red, suffer greatly by it, it gives them a dull and dirty cast; Naples-yellow suffers most of all from it; its vivacity is entirely destroyed by the iron’s touching it. Horn, ivory, or tortoise shell knives, or wooden spatulas are fitter for all manner of painting; they will affect no colours; iron knives have destroyed many a tender complexion in oil-colours; for, the oil once dry, the iron ground off from the knife and mixed in the colours will be converted into rust by the moisture of the air.—Tho’ this little hint is foreign to our present subject, it will perhaps not be unacceptable to my brethren.—It is an essential point in an architect to be acquainted with the qualities and properties of the materials he builds with, if his plan and stile, dispositions, proportions, &c. be ever so good, noble, grand and graceful, yet if his fabric falls down as soon as built, we are but little beholden to his skill.—Vandyke, I believe, never used an iron knife, if he had he would not have painted a spatula of horn in one of his pictures, wherein all the utensils of a painter accompany his own figure.—