To paint on linnen or canvas; the canvas being stretch'd on a frame, they give it a couch or lay of size: when dry, they go over it with a pumice-stone, to smooth off the knots. By means of the size the little threads and hairs are all laid close on the cloth, and the little holes stopp'd up, so as no colour can pass thro'. ,When the cloth is dry, they lay on oker, which is a natural earth, and bears a body; sometimes, mixing with it a little white lead to make it dry the sooner. When dry, they go over it with the pumice-stone to make it smooth.,After this, they sometimes add a second lay composed of white lead, and a little charcoal black, to render the ground of an ash-colour, observing in each manner to lay on as little colour as possible, that the cloth may not break, and that the colours, when they come to be painted over, may preserve the better.,In some paintings of Titian and Paolo Veronese we find they made their ground with water, and painted over it with oil; which contributed much to the vivacity and freshness of their works: for the water ground, by imbibing the oil of the colours, leaves them the more beautiful; the oil itself taking away a deal of their vivacity.