Some materials are employed partly for their decorative effect, such as naturally figured woods and certain varieties of stone; and design mainly consists of judicious selection, use and treatment. Oak and walnut being woods extremely suitable for structural work and furniture have always been in request when obtainable. Polishing is to some extent a preservative, but work in oak or walnut, especially when carved, should be kept comparatively dull, otherwise confusion between the relief and the natural figuring would result. In mahogany or satinwood, where the chief interest exists in the figuring and colour, carving is undesirable and the best effects are obtained by high polish. It may be urged that in the Chippendale period the work was invariably carved, but the detail was always in very low relief, and the finishing dark in colour, in which the figuring was subdued. Mahogany in its more general employment owes its chief beauty to the development of figuring and colour. Certain marbles are used for their decorative effect, and the natural colour and figuring developed by polish. Statuary marble that is sometimes employed, is more suitable for carved details, and appears at its best when unpolished, though in this state it is extremely subject to discolouration owing to its absorbent nature. Granite, so popular in our cemeteries, is often polished, when the natural figuring is unpleasantly aggressive. An extremely hard stone and laborious to work, it is not suitable for carving, and is best left roughly tooled or frosted, when the natural chrystaline formation appears to the best advantage. _Justification of Treatment_ The softer woods used in interior structural work are generally painted, partly as a preservative and largely because they do not possess any figuring of particular interest. Graining in imitation of more precious woods is often condemned as inartistic, but it may be urged in extenuation that it is the most economic treatment, as it helps to minimise the effect of wear and incidental damage. The use of pattern wall-papers and floor coverings can be justified on the same grounds, as in those with plain surfaces any disfigurement is readily seen. Wallpaper, however, is quite a legitimate form of decoration and not necessarily imitative, though to some extent it is reminiscent of the early custom of employing tapestries as wall coverings. A more durable and artistic treatment of interiors is that of the wainscotting of the Georgian period, but the initial cost is proportionately great, though probably when maintenance is taken into consideration it would be cheaper in the long run. Apart from the question of cost, the modern tendency is favourable to change of effect and environment, due partly to the facility afforded by the comparative cheapness of wall-paper, but even more to the prevalent short tenancies. _Undesirable Imitation_