Where a more ambitious colour effect is desired, four warps, each of a different colour, can be employed instead of two pairs. These, combined in different ways with four wefts of various colours, obviously give scope for a great variety of shade and design. [Illustration: FIG. 29 THREE-PLY WARP AND TWO-PLY WEFT. SECTION THROUGH WARP A, Black stuffer warp; B, C, D, E, Coloured warps; W, X, Y, Z, Wefts of same colours as B, C, D, E] The so-called Art Squares—not a very satisfactory name—are generally made with two coloured warps, one cotton chain, and one jute stuffer beam. The design is operated, as, of course, in many other kinds of loom, by a Jacquard mechanism. The blanks or perforations in the pattern cards cause some of the chain threads to be lifted up while others are left down, the space between them forming the shed, through which the shuttle passes, carrying the weft. Where the chain ends only are lifted, the weft will show; where the stuffer is raised, it will cover the weft. There may be three or four shuttles, each carrying a different coloured weft, and one or other of the wefts will appear on the surface of the carpet all along the shot, while the remainder will remain hidden. Sometimes one shuttle carries a cotton weft. In some weaves the black stuffer is occasionally brought to the surface so as to obtain an additional effect, or, alternatively, a two-colour chain warp is employed, without a stuffer. [Illustration: FIG. 30 THREE-PLY WARP AND WEFT A, B, C, D, E, F, Coloured warps; U, V, W, X, Y, Z, Coloured wefts] A more complicated variety of weave can be made with three sets of warp threads, each of two colours, alternately, and six wefts correspondingly coloured. This produces a fabric of three textures, which are fastened to each other at the point of interchange. If, therefore, the design should involve a large area of one colour or effect, this area is apt to be loose and baggy, covering a pocket, which is not attached to the rest of the fabric. This defect, however, can be overcome by utilising one of the warps or wefts to act as a binding thread. As has been intimated above, modern developments of Ingrain carpets have tended in the direction of wide seamless carpets, in which respect the fabric is on the same lines as other classes of carpeting. The bulk of the trade now lies in the wide carpets, and comparatively few breadth goods are woven. The modern Art Square loom is a fine piece of mechanism, inspiring admiration with its comparatively small Jacquard, its mass of cordage, and its ingenious co-ordinated motions. Modern developments of fabrics have also been in the direction of heavier goods and coarser pitches. Most qualities now being made contain 1,088 warp ends to the yard, in stuffer and chain combined. The yarn now used is heavier, as it has been realised that a carpet needs weight, both for the sake of wearing qualities, and in order that it may lie well on the floor.