CHAP. VI.
Of the grounds for the feveral kinds
of painting.
SECT. I. Of the grounds for oil painting.
T H E fubftance or matter on which oil paintings are made, unlefs in very par- ticular cafes, are canvas, wood, or copper- plate. The preparation or covering of thefe,
m order to their receiving the proper colour- ing, muft be therefore different according to the different fubftance in queftion.
The pieces of canvas prepared by proper primings, are then by painters called clolbs. But thefe cloths, though they are difpenfed with in general, becaufe painters think it too much trouble to prime them themfelves, and therefore make fhift with what the colourmen will afford them, who on their fide likewife cbn- fult nothing but the cheapell and. eafieft methods of cmpatching their work, are yet at prefent prepared in a faulty manner in feveral refpe&s. In the firft place, the whole covering' is apt to peel and crack off from the cloth, by the improper texture of the under coat, which is formed of fize and whiting; and is both too brittle, and too little adhefive, either to the cloth or upper coat, to anfwer well the pur- pofe. In the fecond place, the oil ufed in the compofition of any paint ufed on fuch grounds, is extremely apt to be abforbed or fuckt in by them; and confequently to leave the colours, with which it was mixt, deftitute in a great degree of what is neceflary for their proper temperament. This is called, though impro- 1 perly, the jinkingin of the colours} and is attended with feveral inconveniencies; particularly, that the effect of the painting appears very imperfectly while the colours are in this ftate, and deprives the painter, as well as others, of the power of judging properly of the truth of the performance. It is indeed practifed fome- times to varnilh over the ground, which will prevent the finking in j but there is a hazard in this, that the upper coat may leave the
ground ; and the painting confequently come pff, Whoever therefore would have good cloths, free entirely from this difadvantage, rtiuft diredl the preparation of them them- felves; and they may produce them ip perfection by die following means.
“ Let the cloths be firft well foaked with dry-? “ ing oil laid on hot, and when nearly dry, let ** two or three coats of drying oil and red oker, f* mixed as thick as can be worked, be fpread ft over it. Then, the laft being dry, let the f* doth be brufhed over with hot drying oil, f* as long as it appears to link in: and, laftly, f* let it be covered with a coat of white lead tf and oil, rendered grey, or of any other co- ” lour defired, by admixture of the proper ?* pigments. This laft coat may be polifhed to a due degree by rubbing with a pumice f* ftone, or by glazing it with me glafs polilhers f* ufed for linnen, and called callender Jidnes.” In priming wood, or preparing it to receive the oil colours, the fame errors are generally pommitted: for the method almoft univerfally praltifed is to clear-coat it, (as it is called) with fize and whiting; and then to cover it with white lead and oil: but the ill effe&s of fiich a method are ftill greater, in this cafe, than in that of canvas; as if any moifture find accefs to the wood, the paint rifes in blifters, which are liable to be burft, and to caufe a flaking off and peeling of the paint, in a very detrimental manner- For paintings of any yalue die wood fhould, therefore, be brufhed over with hot drying oil, as long as it will foak it in; and then covered with a coat of white lead, or flake, coloured according to what may be delired. Even in the cafe of houfe or coach painting, the clear-coating with fize and whiting, ought to be omitted; and, in its place, a coat of drying oil with fome white lead and oker, but not fo much as to make it ftiff, fhould be ufed as the firft priming, in- fteadof the fize and whiting; which method would both preferve the wood much better, and prevent both the buffering and peeling; and in fbme degree the finking in of the colours that attend the common method.
When copper-plates are ufêd, there is no occafion for any other priming than one coat of oil, and lead, or oker, rendered of the colour defired: but fitch plates are foldom employed but for delicate and elaborate paintings. The furface of the priming ought to be made as fmooth as the plate itfelf, by rubbing with the pumice ftone, or glazing with the callender ftone. But there is another method very effectual for making a fine ground on the copper-plates; which is the ufing flake white and fat oil, with any colour required; which being laid on the plates placed in an horizontal pofition to dry, will poiifh itfelf very highly, by the running of the oil. The oil ufed for this purpofe fhould be thoroughly fat: which, though not at prefent to be had of colourmen, may be eafily made by thé method below taught, with very little expence and trouble; and this method of producing grounds by fat oil, perfectly fmootn, fecured from any finking in of the colours, and in all other refpefts much better than any other, may t>e pra&ifed with advantage on cloths or wood, well as copper-plates; the cloths being firfl ^prepared for the laft coat in the manner before <3iredted; and the wood foaked with drying oil.