Over all these sizings we can paint equally well in oil or water-colours. Only one question regarding the sizing remains to be considered: and that is, what tone we should prefer to give it. We do not hesitate to answer that the sizing should be perfectly white, and that for several reasons. First, to obtain effects of transparency without the necessity of painting in oil-whites and afterwards glazing, which involves waiting a long time until the under coatings are dry, and sends us back into all the inconveniences of oil sizing. Secondly, because the under coatings always work up a little, and a picture, painted over a coating of any tone whatever, will ultimately always become itself of that tone, especially in those parts least covered. Certain pictures of Poussin and of the French school of the eighteenth century, painted over red coatings, are striking examples of this. Some artists have preferred umber, and even pure black, but their works have not lasted a century. Their pictures have become quite invisible, in half tints, at the end of a very short time. , ,Apart from the preservation of the picture, there is another important consideration -viz., white foundations naturally cause greater luminosity and that is a valuable quality; darkness always comes on soon enough.",,