SCHAPPE. A term denoting a particular type of yarn spun from "schappe" waste silk from which the natural gum, termed sericin has not been entirely removed or discharged either by "boiling-off" by the English system of "degumming" raw silk, or by the alternative Continental system of fermentation, known as "schapping." The waste silk so treated is soft and lustrous, with the fine silk filaments free from each other, yet retaining some of their natural gum. Schappe silk varies from a white to a bright yellow tone according to the amount of gum still present.
Schappe also denotes a particular type of silk fabric sold under that trade-name and produced from two-ply "schappe" spun silk yarn which, before bleaching, has a somewhat yellow tone owing to the presence of the natural gum. A schappe silk fabric is a fairly strong and firm texture of medium weight, woven on the principle of the plain calico weave, but having a slightly fine ribbed effect somewhat similar to that of a fine "poplin" (q.v.)
texture but with the ribs or cords much less pronounced. This fine ribbed effect is developed by employing warp yarn of finer denier or counts than that of the weft, and also by inserting a greater number of warp threads than picks of weft, per inch, in the fabric. Thus, one example of "schappe" silk fabric contains 104 warp threads of 52's/2, and 72 picks of 40's/2 weft, per inch.
These denominations of yarn counts are equivalent to 52's and 40's counts of single cotton yarn respectively. They are produced by folding and doubling together two silk threads each of 5o denier silk (approximately) to produce the 52's/2 silk thread, and two threads each of 65 denier silk (approximately) to produce the 40's/2 silk thread. (H. N.)