Take a piece of prepared canvass such as is used for oil paintings, selecting that which has the smoothest and most level surface, and the whitest colour. Mix flake white with nut or poppy oil, to such a degree of stiffness as that you may be able to work it with a hog's hair tool tolerably well; if it be made thinner, the board or canvass will be rendered coarse. Let the paint be drove bare and level as possible, and when the surface is completely covered, take a flat badger's hair brush, using it with a light hand in every direction, until the face of the paint becomes perfectly smooth; after which, take very fine powder of white marble, and putting it in a small sieve, sift it plentifully on the canvass, holding the frame nearly perpendicular, and turning it every way, still lifting more and more powder thereon. Shake or beat off the superfluous dust, and in two or three days when the paint is dry, remove the remaining loose particles of powder with a clothes brush, and it will be ready for use. A small quantity of sugar of lead should be added to the white paint to facilitate its drying. If a warm tint should be required for the ground, yellow ochre must be mixed with the white, as may be required.,,Flake White is usually procured at colour shops, ground and tied up in balls, as also the sugar of lead. The white marble is ground with a muller and slab similar to those used by painters, and with pure water, after which it must be dried. The powder should not be quite impalpable. With a marble muller it may be ground without water.