Pongee is a soft, unbleached, washable silk, shipped from China to Europe in large quantities, where it is bleached, dyed, and ornamented in various styles of designs. The name is also applied to a variety of dress goods made in Europe woven with a wild-silk warp and a fine worsted weft. This material is of comparatively recent make and is made mostly with narrow stripes, produced by the insertion of certain yarn-dyed threads.
Silk Seal (Cotton Back).—This is an imitation fur fabric made in a range of quality, length, and closeness of pile. In this fabric the pile only is of silk, the foundation cloth being all cotton.
Silk Seal might be mistaken for Silk Beaver if not judged from the point of view of colour. Silk Seal is black, Silk Beaver is brown. There is a variety of this fabric known as a Fancy Silk Seal, similar in construction and components but having stamped in outline by means of rollers a design resembling the irregular scales on a crocodile's skin. Along the lines demarcating these scales the pile has been crushed and fixed down by heat. This fabric is not a true Silk Seal. Quality in this, as in other pile fabrics, depends on the closeness and depth of the pile. There is a possibility of mistaking Silk Seal with cotton back for a Silk Plush with cotton back, but generally the pile of Plush is shorter than that of Silk Seal. Average width, 48 to 50 inches.
Silk Yarns.—There are two distinct classes of silk yarns, i.e., (a.) pure, or net, silk and (b.) spun silk.
(a.) Net Silk Yarns.—These are constructed from fibres reeled straight from the cocoon, and in the case of organzine (or warp) yarns three to eight fibres are lightly twisted together; subsequently, two or more of these compound threads ("singles" as they are termed) are folded together to form the silk yarn employed as warp. Weft yarns, known as tram silk, are made from two or more strands, each made from three to twelve cocoon fibres, which have not undergone any preliminary twisting, so that tram silk is much straighter, softer, and more lustrous than organzine.
(b.) Waste and Spun Silk Yarns.—The fibre is obtained from "pierced" cocoons, i.e., cocoons through which the silk moth has forced a way at the time of emerging from same, also from "wild" cocoons. The low qualities are short-fibred and are only suitable for weft yarns, while the longer drafts produce higher quality yarns well suited for warp.
Counts of spun silk are based upon two distinct systems of numbering. In the French system the number is based on the singles, by metres per kilogramme; two and three cord yarns have one-half, one-third, etc., the length the numbers indicate thus:—
| No. | 100 singles | has | 100,000 | metres | per kilogramme. |
| " | 2/100 | " | 50,000 | " | " |
| " | 3/100 | " | 33,333 | " | " |