There are many beautiful colored silks. Silk is usually dyed (Fig. 79) in the yarn in hanks. The poor qualities, however, are dyed after the silk is woven into the piece. Silk is dyed by dipping the skeins or yards of silk in great vats of dye. For dyeing, the coal-tar products (aniline dyes) are used. Did you know that coal could produce such beautiful colors? That is a long story of the many wonderful things which can be made from tar. Do you know that 25 per cent of the weight of the raw silk is made up of the gummy substance? The dyer boils out some of the gum; and, if he wishes to produce cheap silks and make much money, he makes up for the weight of gum boiled out, by using tin. The silk is dipped in bichloride of tin or other substances; and it takes up, or absorbs, until sometimes it weighs twice or even four times as much as the boiled-off silks. This tin is bought for silk. Women who do not know think they are buying heavy silk and are getting a good quality because it is so heavy. This solution of tin rots the silk, and, when the silk comes in contact with light and air, it crumbles away. Perhaps you have at home a sample of silk which has done this. Marjorie's Cousin Ann saw some petticoats of silk which went to pieces just hanging in a closet. Sometimes that happens when store keepers keep the petticoats for some time. One can see the holes by holding the silk up to the light. In order to know what one is buying one must study about materials and about how they are made.
Courtesy of Cheney Bros.
Fig. 80.—Warping or preparing silk for the loom.
Have you ever seen a picture of silk being dyed in the skein? Marjorie's cousin says it is done by machinery. See how many skeins are on the big wheel, or drum as it is called. As it turns, the skeins are dipped in the vat of dye.
Courtesy of Cheney Bros.
Fig. 81.—Silk weaving on a hand loom in Japan.
After the warp threads are twisted and wound on spools, the workman places the spools in racks (see Fig. 80). They are then unwound again on to a very large roller, as you can see in the picture. The large roller is then put into the back of the loom, and the warp threads are drawn through and prepared so they are attached to the roller where the cloth is to be rolled after it is woven. Do you remember how we found the cloth and the warp rollers when we were studying about how cotton cloth is made? For plain silks a loom is used very much like the looms for weaving cotton cloth (see page 69); but, for fancy silks and beautiful patterns and designs, the Jacquard loom like the picture (see page 124) is necessary. This wonderful machine was invented by a Frenchman, Joseph Marie Jacquard, in 1801. The cards are cut in tiny holes which regulate the pattern and make beautiful designs. The cards control the warp threads and regulate which threads are to be up and which down, as the shuttle passes over and under. The shuttle is lined with soft seal skin to protect the silk fibers of the filling thread on the bobbin as they unroll.