When the plaster is first put on, of course it is very soft; the piece of cartoon is replaced upon it, and the lines of the picture are gone over with a bone point, so that an indentation is made, and then the artist begins his painting. At first he finds his colours work greasy; you cannot get the tint to lie on, it works streaky; but you must not mind that, you must paint on, but you must only paint on for a certain time, for if you go on painting too long you will interfere with the satisfactory suction of the ground, which is so necessary to produce a good fresco painting. Of course, nothing but practice can tell any one the period at which he ought to stop. After some practice, you know perfectly well by the feel when you ought to stop. If you feel your colour flowing from your brush too readily, you ought to stop at this period. You must then leave your work for a time, and go back to it again. And then you will find, as the plaster sucks in the colour which you have first laid on, that there will be--it may be in the course of half-an-hour, it may be an hour, that depends upon the temperature of the atmosphere--a pleasant suction from your brush, the colour going from it agreeably, and you will find that it will cover better. Now is the time to paint rapidly, and complete the work you have in hand. When the colour leaves your brush as though the wall was thirsty for moisture, you should cease painting; every touch that is applied after that will turn out grey when it dries, and the colour will not be fast upon the wall. You will see, then, how impossible it is, with such materials, to paint in the same style in which you paint a picture in oil-colour. Fresco painting involves the adoption of an entirely different style from oil painting. The frescoes of the old masters are not highly wrought up, highly-finished works. They depend for their effect upon the juxtaposition of tints, the shadows being intensified by lines and cross-hatching. If you look at those reproductions of some of the most valuable fresco paintings of the old masters, you will see the method adopted by them depended upon the juxtaposition of tints, not upon covering over, and over, and over again. That juxtaposition of tints produces roundness, transparency, and has a very pleasing effect upon the eye. If two tints are put against one another, they do not appear to us as if they were single, but each adds something to the effect of the other, and together they produce a pleasurable and agreeable effect, if they have been properly selected. We all know how tempting it is to go back to a piece of painting and do something to it that ought to have been done before. We think that a touch will improve it, and we go and make it: but in fresco painting the temptation must be resisted, for it will be absolutely fatal to the permanency of the work. INDEX African indigo, 47 Alkali for removing old paint, 351 Alumina for lakes, 282 American indigo, 47