Before commencing to lay on the ground, it is well to wash the surface of the vase with a thin solution of glaze (such as is used for finishing the ware), or with borax water. This is to ensure the adhesion of the clay, of which the painting is to consist, to the clay of which the vase is made. Previous to this, the vase, if not already in good condition, should be washed over with a brush, or with a sponge dipped in water, or sprinkled until it has absorbed water enough to keep the clay, which is to be applied to its surface, from drying too quickly. A broad, flat camel’s-hair brush may then be charged with the _light tint_, and the surface of the vase covered with it as evenly as possible, and so thickly as to completely obscure the body. This done, another tint, darker than the first, in a degree sufficient to permit their being distinguished from each other, may be mixed. This will form the middle tint of the ground, and is to be laid on over the first. The reason for applying two coats is, that, although it might be possible to paint one with the degree of thickness necessary to prevent the shrinkage of the applied clay in the firing, from revealing the body of the vase, still the beginner is very likely to be deceived as to the thickness of the _impasto_, judging by the eye alone. Potters dip pieces of ware in colored slips, and the thickness of the covering thus formed is all sufficient. In the case of painting, however, it is impossible to lay the clay on as evenly, and there will be, in all probability, some places too thinly covered to stand the fire, but which would not be revealed before. It is better, therefore, to apply two coats, so that one may cover up the deficiencies of the other. The reason for having these two coats of different tints is, that it is then possible to be assured that the surface is covered completely, it being easy to distinguish the first tint laid from the body of the vase, and in the second painting, to observe that it entirely covers the first. The second coat finished, a lighter tint should be mixed, with which the ground is varied by touches here and there, making the highest light of the ground, while touches of the first tint mixed, give the darker shades. There should be difference enough in tone between the middle tints of the ground, and these lighter and darker tints, to produce a good effect of light and shade, and these touches should be laid on with a free hand, and then softened into the ground, care being taken that the lights and shadows should not end too abruptly.