Late 19th century Venetian woman shoe, cream silk

Weighted silk is

silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the coc ...

which has been treated to restore or increase the weight lost during the process of

degumming Sericulture, or silk farming, is the cultivation of silkworms to produce silk. Although there are several commercial species of silkworms, ''Bombyx mori'' (the caterpillar of the domestic silkmoth) is the most widely used and intensively studi ...

. This processing started in the 19th century, with vegetable-based solutions such as

tannin Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' (from Anglo-Norman ''tanner'', ...

s or

sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...

. Chemical solutions based upon

salts In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively cha ...

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...

tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...

were then used, as well as

silicate In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is al ...

, phosphate of soda, and astringent extracts. These increased the weight considerably, but led to accusations of adulteration as the properties of the silk were impaired.

Process and history

Unlike most fabric/yard goods which are sold by the yard (or metre), silk is sold to the wholesaler by weight; however, as the first step in processing silk fibre is to "degum" it - removing the

sericin Sericin is a protein created by ''Bombyx mori'' (silkworms) in the production of silk. Silk is a fibre produced by the silkworm in production of its Pupa#Cocoon, cocoon. It consists mainly of two proteins, fibroin and sericin. Silk consists of ...

from the fibre, a protein naturally produced by silkworms that coats silkworm cocoons - approximately one-fifth of the weight of silk fibre is lost, representing a significant drop in the saleable price of processed silk fibre. As such, silk fabric manufacturers would historically "replace" this lost weight with a 'filler', which would add weight to the fibre and thus make up the cost. Silk has an affinity for several metallic salts, the most common of which being

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

, and

. It was discovered to be an easy process to return this weight lost in the degumming process by soaking the fibre in a bath of these metallic salts. This process was called 'weighting', and by increasing the weight of the raw silk, the merchant increased their profits. Weighting with some metallic salts did improve the drapeability of silk fabrics; however, merchants soon began adding more weight than the lost one-fifth, with the final weight of the fabric sometimes increased tenfold. In 1938, the U.S.

Federal Trade Commission The Federal Trade Commission (FTC) is an independent agency of the United States government whose principal mission is the enforcement of civil (non-criminal) antitrust law and the promotion of consumer protection. The FTC shares jurisdiction ov ...

ruled that silk that weighted more than 10%, and black silk that weighted more than 15%, must be labeled 'Weighted Silk'. While silk is a strong and durable fibre, the weighting process is highly damaging to the finished fabric and resulting garments. If the garment is worn, it wears out quickly and is highly susceptible to damage from perspiration, salt, and tears; if stored away, it becomes brittle and begins to shatter along lines of wear at an expedited rate. The method of storage does not ameliorate the process of damage introduced by the fabric's weighting, with storage in cold, dry and dark areas doing little, if nothing, to prevent further damage. Examples of antique weighted silks displaying this damage are easily seen, such as in antique American "crazy quilts", where the silk fibres have disintegrated, whilst the

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor perce ...

and

wool Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool. As ...

fibres remain in good condition, even after 100 years. A later example displaying damage resulting from tin-weighting is the

wedding dress A wedding dress or bridal gown is the dress worn by the bride during a wedding ceremony. The color, style and ceremonial importance of the gown can depend on the religion and culture of the wedding participants. In Western cultures and Anglo-Sa ...

of the future

Elizabeth II Elizabeth II (Elizabeth Alexandra Mary; 21 April 1926 – 8 September 2022) was Queen of the United Kingdom and other Commonwealth realms from 6 February 1952 until her death in 2022. She was queen regnant of 32 sovereign states during ...

, then Princess Elizabeth, of the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

; the fabric, a tin-weighted Chinese silk chosen especially by

Queen Elizabeth the Queen Mother Elizabeth Angela Marguerite Bowes-Lyon (4 August 1900 – 30 March 2002) was Queen of the United Kingdom and the Dominions of the British Commonwealth from 11 December 1936 to 6 February 1952 as the wife of King George VI. She was the l ...

, began to rot just 30 years after the dress had been created, with the weight of the dress' embroidery worsening the fabric's condition further. The practice of weighting silk was widespread in the 19th century, and decreased somewhat in the 20th, but is still used to some extent. In the early 20th century, fashion trends had changed substantially and heavier silks fell out of popularity. A lighter silk was preferred and thus weighted silks were less used. An alternative to weighted silk is "

organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ...

silk", wherein the sericin is not removed from the fibre before processing, and is instead left in.

Process and history

See also

References

Further reading