Concerning excellence in the design of wall papers and cloth fabrics, we have noted in earlier chapters that, in general, size of pattern, or effect of texture, or both, will increase directly with the size and structural emphasis of the room; that the amount of pattern and the number of colors in a wall paper must be decreased as the quantity and number in the other surfaces of the room are increased; and that while the ornamental detail in a paper may be drawn from nature, it must, except in the case of hand-blacked landscape papers, be highly conventionalized.

While a paper intended to serve as a background for pictures or for other objects of marked decorative value must have a pleasing texture, it will normally be, either plain or covered with an inconspicuous self-toned pattern. Water colors, pastels and etchings used in a small room will look best against plain walls. Large heavily-framed pictures in a large room will look better on a coarse or open texture, or, where the proportions of the room demand it, against a medium-sized and symmetrical pattern in a self-toned paper. In a room without pictures or other wall ornament the wall paper may, of course, reveal a more pronounced pattern and richer coloring; but even here it is to be remembered that in the background surfaces of any room to be used regularly and for long periods of time cultivated people can endure but a very moder-ate degree of stimulation. The gorgeous papers that one sees in the shops or reads of in the books can be hung successfully only in rooms used infrequently or for short periods; and even then they can be employed safely only by skillful decorators. In the hands of beginners the use of such papers is practically certain to result in unpleasant and inartistic rooms.

All wall papers, except the hand-blocked scenic papers so much used at the end of the eighteenth century, have of necessity a repeating pattern. Unless the repeat is wholly concealed, as in the case of shaded or blended papers, it should be clearly revealed and even emphasized. For this reason diaper patterns are likely to be far more agreeable when hung than detached figures in which the ornament, though constantly repeated, is set off by plain spaces. Such papers have a spotty effect, and an insistence of appeal that catches the eye and wearies the mind. It is to be noted that fairly small patterns, and ornament either purely geometrical in character or else very highly conventionalized, are best suited to repeating pattern design, whether in wall papers or carpets, and that in the degree that patterns are very large, markedly naturalistic in rendering, or of a strikingly exotic character - as in the Chinoiseries so much the rage in the last quarter of the eighteenth century and so much copied in recent years - they become less well adapted to the requirements of repeating ornament and less pleasing when so used.

The number and variety of colors that can be effectively used in the design of a paper varies inversely with the size of the pattern. In small patterns the colors appear in such minute areas, and so closely juxtaposed, that the eye feels no sense of confusion. In large figures, on the other hand, the number of colors must be narrowly restricted, and the best effects are almost invariably produced in patterns limited to two or three tones of a single hue.

The esthetic function of the floor coverings is, in general, to provide a low-toned and restful base for the decorative treatment. It is a mistake to assume that the ideal floor covering is always the plain rug or carpet. Plain carpets affect the mind precisely as do other plain surfaces, and they are desirable only when they concur in the proper expression of the emotional character or motive of the room as a unit. The ideal floor covering, abstractly considered, is rather the one which is both low in tone and broken in hue, since such carpets yield the effect of stability essential in the base of the room, and at the same time make it possible to give a subtle interest to the color treatment by echoing in small and broken masses on the floor the larger masses of more brilliant colors appearing in the decorative objects placed nearer eye-height. On the other hand, the carpet must not in the modern room make an over-insistent demand for attention. In Persia and Turkey there are no pictures and but little furniture, and the rugs constitute the chief decoration of the room. With us the finest rug is but one part of a much greater whole, and the decorator must be careful to keep his floor covering, like every other individual element, carefully subordinated to the general scheme.

In the design of floor coverings the essential conditions are flat surface and uniformity of appearance as seen from any point of view. The first requirement definitely bars all effects of perspective or relief, which cause one or more elements of the design to seem to be in a higher plane than the others. Such effects appear when bright flowers or other ornamental motives are related to a darker ground by shading, as well as in shaded self-toned ornament. Flatness of surface is characteristic of all good Oriental rugs, and where rich color effects are demanded in the design of a domestic rug or carpet this essential flatness can be best ensured by using colors in the Oriental manner; that is, by defining flat masses of color and relieving forms by means of narrow outlines of other colors, and by eliminating all effects of shading.

Violations of the second requirement are common, even among the finest domestic carpets and rugs. They result chiefly from the practice of copying successful wall paper and drapery patterns in floor coverings, and arise from failure to distinguish between the artistic requirements of vertical and horizontal surfaces. Every wall surface has a bottom and a top, and vase, vine, flower and tree designs are, if properly conventionalized, perfectly appropriate for wall work because no one can see them from the top. Floor coverings, on the contrary, must be seen from every point in the room, and a pattern having a pronounced direction will necessarily appear to be upside down when seen from one end of the room.