Varnish.

Painting plastered walls.

Size colors.

When badly mixed or put on, however, fresco painting is likely to give trouble in various ways. It is usual to brush a new wall or ceiling over with thin glue size as a preliminary to painting, in order to fill the pores, and prevent the plastering from absorbing the water unevenly from the paint; and, after the size is dry, the color is put on as rapidly as possible, in one coat. If the preliminary sizing has been imperfectly done, the absorption, or "suction," of the plastering will show itself in uneven patches in the finished work. If the sizing is properly done, the finished painting may still be uneven, through insufficient mixing of the paint before it is put on. Where the preliminary sizing has been too heavy, or the paint is mixed with size either too strong or not strong enough, or if the plastered wall is old and greasy, the paint may come off, either in fine powder, or in little chips. In any of these cases, the only remedy is to wash the wall or ceiling off with hot water and a sponge, and paint it over again. It is not usually necessary to size it a second time, if the sizing was originally well done, as the washing does not remove the glue from the pores of the plastering. Even if the defect is a small one, the washing of the whole wall or ceiling with hot water is a necessary preliminary to treating it, as it is impossible to patch or retouch size color, the junction of the old and new work always showing as a dark, shining line. Fortunately, size and whiting are cheap, and the process of putting on the color is a very simple one, so that washing off and repainting, if the first attempts are unsuccessful, is not an expensive matter.

Notwithstanding the beauty of size colors, the impossibility of retouching them successfully makes it desirable in houses of the better class, where washing off a wall or ceiling would involve the moving of much costly furniture, and perhaps endanger expensive floors and woodwork, to paint the plastering in oil. For this purpose it must be sized, as it is even more necessary to check the "suction" of a wall to be afterward painted in oil than where size colors are used. Usually, the size, which may be either ordinary glue size or varnish, is put on as a first coat; but there are some advantages in putting on a coat of paint first, and the size over it. In any case, at least three coats of paint will be required, in addition to the size, to give a reasonably even surface. As ordinary oil paint is glossy enough to reflect the light at certain angles, every unevenness in a wall covered with it is revealed; so that it is usual to deaden the gloss of the last coat, either by mixing it with turpentine alone, or by going over the entire surface, while the paint is still wet and soft, with a stiff brush, which is touched to the surface so as to raise the paint in little waves. This "stippling" leaves the paint with a washable surface, and is for this reason to be preferred to "flatting" with turpentine, which, although it gives a pretty surface, leaves the wall very susceptible to marks of all kinds, which are not easily removed, since a "flatted" coat can hardly be washed without leaving streaks, and can be patched or retouched only with difficulty, as color mixed with turpentine alone dries with a dark edge, like colors mixed with size.

Oil-painted walls.

To the average householder, the conception of a room involves the idea of paper on the walls; and wall-papers still form the mural decoration of the vast majority of houses. They have the advantage over paint that they do not show scratches and wear so quickly; that they are easily changed or renewed, and that they help to "furnish" a room otherwise, perhaps, bare, besides in many cases offering real artistic charm. On the other hand, some papers soon fade and look shabby; some contain very poisonous colors, which give off either deleterious dust or noxious vapors, or both; and all of them are put on with flour paste, which slowly putrefies, with the production of the acrid, musty emanations characteristic of old houses. In point of expense, there is not much to choose between painting the walls of a house, and papering them. Although some of the cheap wall-papers are very pretty, the cost of putting them on has advanced greatly within a few years, being often several times as much as that of the paper itself; so that, in general, a wall can be painted in size color more cheaply than it can be papered, even with the cheapest paper; while painting in oil costs somewhat more than papering with a cheap paper, but much less than papering of an expensive character.

Flatting.

Stippling.

Wall-papers.

Artistically, the choice between paper and paint depends upon several considerations. While walls simply painted unquestionably look bare in comparison with those covered with paper, this is sometimes an advantage, as in summer cottages, to which they give a feeling of space and air, and in rooms containing a large amount of furniture, where they improve the effect of the furniture by affording a plain background, where a figured paper would produce a sense of wearisome confusion. Where pictures are to be hung, also, either a painted wall or a plain paper is much to be preferred to a figured paper. Very frequently, figured and plain papers, or figured papers and paint, are used together with good effect. The old William Morris system of papering the wall of a room to a height of about four feet from the floor, finishing at that point with a moulding or a black line; then painting with a plain color from this level to within about sixteen inches of the ceiling, and finishing with a figured paper frieze, so that the pictures come against a plain background, while the upper and lower divisions of the wall are decorated, can hardly be improved upon, if the colors of paper and paint are judiciously selected, for living-rooms of moderate size, particularly if they are irregular in shape.