Many excellent designs are produced in wall-papers, though there is a tendency at times to reproduce textural effects which can only be justified on æsthetic grounds. Those of the frankly imitative kind cannot be condoned. It is still possible to have the hall and stairs papered and varnished to resemble slabs of precious marble, or patterns in mosaic, which were undreamt of in Byzantine times; and the orthodox design for the bathroom is still that of tiles with the joints neatly printed. Similar imitation is also apparent in linoleum, when the pattern simulates the appearance of either wood parquet or mosaic, or even worse--that of a Turkey or Axminster carpet. There is an element of priggishness in such cheap art in which, as though ashamed of poverty of material, there is an assumption of something better; and it is lamentable that there is not merely a market for these shams and imitations but curiously enough they also find appreciation. There are phases of work where simulation may to some extent be justified, for instance, silver is sometimes gilt. For this there is the excuse that silver, although a beautiful metal, is subject to oxidation and requires constant attention to keep bright. Gilding acts as a preservative, and is therefore justified in certain forms of silver work, which it is not convenient to clean in the ordinary way. _Technical Considerations_ It has already been suggested that Design is not merely a question of idea and draughtsmanship, but is also dependent upon materialistic conditions, which, in practical work, must be understood and properly considered. Whether the intended design be for some form of flat pattern, such as weaving, etc., or for any particular craft expression, it is essential that the limitations of the process and material involved be clearly kept in view, and that suitable elements for expression be chosen. Convention, to a large extent, exists in the adaptation of forms, natural or otherwise, to the exigencies of production, a proper understanding of which will not only tend to economy in cost, but also to more effective results, if full advantage be taken of the craft or mechanical conditions, which should always be foreseen in design. _Methods of Expression_ Methods of expression vary, according to position and material, and may be Flat--either silhouette, or with appearance of relief, or in actual relief. [Illustration: No. 254. A. B. C. Flat Treatment, Silhouette important. D. Relief Treatment of C.] [Illustration: No. 255. A. Flat Treatment. B. Relief of Husk Leaf.] Contrast exists always, thus in the Flat with or without outline the contrast is in Light and Dark, whether colour is involved or not. In Relief the contrast is in Light and Shade. Contrast exists also in both treatments in lines straight and curved--in the variety of the latter, in lines with mass forms, and in dominant forms with smaller detail.