The substance or matter on which oil paintings are made, unless in very particular cases, are canvas, wood or copperplate. The preparation or covering of these, in order to their receiving the proper colouring, must be therefore different according to the different substance in question. The pieces of canvas prepared by proper primings, are then by painters called 'cloths'. But these cloths, though they are dispensed with in general, because painters think it too much trouble to prime them themselves, and therefore make shift with what the colourmen will afford them, who on their side likewise consult nothing but the cheapest and easiest methods of dispatching their work, are yet at present prepared in a faulty manner in several respects.,In the first 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 size and whiting; and is both too brittle, and too little adhesive, either to the cloth or upper coat, to answer well the purpose.,In the second place, the oil used in the composition of any paint used on such grounds, is extremely apt to be absorbed or suckt in by them; and consequently to leave the colours, with which it was mixt, destitute in a great degree of what is necessary for their proper temperament.,This is called, though improperly, the sinking in of the colours.,,,