Hints on Choosing Textiles 1549 



Their colors are fast and are less likely to fade than are those of 

 cheaper materials made from wool. 



SILK 



The fiber that is the finest and most lustrous of all is that spun by the 

 silkworm as it makes its cocoon. One filament of silk may be as long as 

 four thousand feet, and about five double filaments are required in order 

 to make up the thickness of a strand of raw silk. These long, perfect 

 filaments are taken from the cocoons when the silkworm has been killed 

 by the heat. If the moth is allowed to hatch, the filament is broken in 

 many places and a second-grade product, called spun silk, must be made 

 from the less lustrous, broken fibers. 



In the raw state, silk is sold by the pound. Three thousand silkworms 

 are required to spin one pound of silk, and one to two pounds are required 

 in order to make a dress. When these statistics are considered it will be 

 seen why good silk must necessarily be expensive. There is demand for a 

 product at a moderate price, however, in order to satisfy which the manu- 

 facturer resorts to methods of adulteration. 



Adulterations 



Silk fiber has the quality of absorbing metallic salts and dyes without 

 appreciably changing the external quality of the material. This process 

 of weighting silk is often carried to the extreme, and the fiber is then 

 forced to absorb even more than its own weight of metallic salts. This 

 seriously interferes with the durability of the silk, and as a result the silk 

 splits or falls apart before it has stood even a reasonable test of wear. The 

 durability of present-day silk falls far short of that of our grandmothers. 

 When rightly treated, the silk fiber is very durable. 



Cotton threads are interwoven with silk, especially in sateens, velvets, 

 and brocades, in which they may be entirely hidden. 



Mercerized cotton is often used in silk manufacture, and its glossy 

 appearance may easily be mistaken for the fiber that it imitates. 



Tests for adulteration 

 When burned, a sample of silk will give forth the odor of burning feathers 



that is distinctive of the animal fibers. 

 If silk is heavily weighted, the mineral ash will retain the full size and 

 shape of the original sample but will fall apart at the touch. 



Suggestions 

 Silk is light in weight, has a beautiful luster, and can be woven in many 

 ways so as to give attractive results in beauty of texture and design. It 



