Jacquard Weaving and Designing

by T. F. Bell

If it was required to make a pattern similar to [Fig. 83], but with five figures instead of four, and preserve the same density of ground structure round them, it could be calculated as follows:—[Fig. 83] is on 44 checks broad and 44 long. Now 44 × 44 = 1936, and on this there are four figures, then 1936 ÷ 4 = 484. As five figures are required 484 × 5 = 2420 checks for design. If there are to be as many checks across the design as up it, find the square root of 2420 for the number of checks, as [sqrt]2420 = 50 nearly. If the pattern is not to be square, the proportion may be found for each side by making two calculations, one for the greater number of checks squared, and the other for the lesser number of checks squared, and extracting the square roots for the two sides of the required pattern; or, suppose the warp to be to the weft in the proportion of 10 to 12, then state, as 12 is to 10, so is 50 to 42, the number of checks across the bottom of the pattern; and as 10: 12:: 50 to 60, the number of checks in the length of the pattern, and 42 x 60 = 2520, which is nearly the same as 50 squared = 2500 for a square pattern. But if this is for adding extra weft to the cloth, the size of the pattern would be reduced, which might bring the figures too close together and would alter the shape of them; in this case the addition should be made to the number of checks in length, making the pattern 50 broad and 60 long, or to contain 3000 checks, and the length of the figures should be increased in proportion. Of course this will produce a finer cloth. [Fig. 84] is a pattern arranged with five figures on it.

A great variety of patterns may also be formed by arranging dice or squares in various ways, some of which, as may be seen on the Indian fabrics, make very pretty patterns. It will thus be seen that there is plenty of scope for the ingenuity of a textile designer without his being of necessity a draughtsman; but a knowledge of drawing will generally be of assistance to him. For the more elaborate patterns, the designer does not require to have the same knowledge of manufacturing that is required for these small patterns.

Fig. 85

Twilling.—It has already been shown how the patterns are bound or twilled to form the texture of the cloth for ordinary repeating patterns on a straight over-tie; but when a turn-over or gathered tie is used, the twilling of one half of the gathered portion will, on the cloth, be the reverse, or run in the reverse direction to that of the other portion, and this is often a disadvantage to this description of tie, as one half of the border or pattern, whatever it may be, will look coarser than the other. It frequently happens that to avoid the stiffness of a clean turn-over pattern, which must always have a clear cutting line through the centre of it, so that, if cut up, one half would, if turned over, be exactly the same as the other, a portion of single, or a turning portion, is placed in between the two turned-over portions, which in many cases adds very considerably to the effect of the pattern, though it is often almost useless. [Fig. 85] is a pattern of the turn-over type, and, but for the interlacing of the bands in the centre, might be wrought with a simple gathered tie. For this pattern the portion marked B would require to be single, and A turned over to C. Perhaps it is in floral patterns that this form of tie is of most service. When a single tie takes up too much machinery, and a double over or gathered tie would make the pattern too stiff, a small portion of single introduced, as at B, is of great service to the designer in making a pleasing pattern.

Fig. 86

When twilling a pattern of this description, the portion marked A would be twilled straight across, and this twilling would be continued to the centre of B, as shown in [Fig. 86], which gives the idea, the spots in the centre being taken as the single portion. The portion marked C is repeated from the first part A by the harness, and does not require to be put on the painting; in the figure it is shown (in different type) as it would fall on the cloth. It may be seen that the twilling dots on the last line of A and the first line of C are alike, and that every pair of lines corresponds, moving from these to the edges of the pattern. Now a turn must be made in the twill in the single portion so as to make it join correctly with C, and this should be done in such a manner as to prevent it from showing plainly on the cloth, or having too long floats on some of the threads while others are too closely bound. This must be done by setting the dots out of their places on a few lines in the centre, so as to make the join produce as even a texture as possible. Advantage should always be taken of any portions of the pattern that come on this part, such as the spots in [Fig. 86], to turn the twill round the edges of them. By following the dots on the design paper, it will be seen how they are brought in at the join. Any twill may be broken similarly, but a different number of threads in the single will alter the arranging of the dots to join the two twills together; however, when the principle is understood, it can easily be worked out.