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R.K. Laros Silk Company collection

Identifier: IAL-2019-021

Scope and Contents

The R.K. Laros Silk Company Collection includes materials from the R.K. Laros Silk Company and its successor, the Warner Brothers Company. Materials include pamphlets, booklets, and some stationery from the company, as well as photographs of the plant and its operation during the first half of the twentieth century.


  • 1929 - 1948

Conditions Governing Access

This collection is available for research.

Conditions Governing Use

Materials in the collection may be protected by copyright, and should only be used for Fair Use purposes. For further information, contact IAL at

Biographical / Historical

The R.K. Laros Silk Company was founded in early 1919 by Russell Keller Laros. The original factory opened in Miller Heights, in the eastern part of Bethlehem, PA, where it began as a silk throwing operation, the process of taking the raw silk into yarn or thread.

By 1922, a larger factory opened up on East Broad Street in Bethlehem, PA, which allowed for great production. They also expanded from mere silk throwing to retail production, including manufacturing of lace. Around 1926, the company expanded into silk slip production. So successful were these products that a subsidiary company, the Laros Textiles Company, was founded.

In the mid-1920s the company published the "Laros Data Book" which was a technical document with measurements and criteria for silk thread quality. It was used as a standard in the industry.

During the Great Depression, the Laros company employees never went on strike, despite around 8,600 Lehigh Valley textile workers walking out in 1931. Indeed, the company operated at capacity throughout this time, and approximately one in eight pairs of stockings in the United States was produced at the Laros plant on East Broad Street.

The 1930s showed an expansion of products manufacutred. The "Perma-Lokt" seam was developed, earning significant commendation. In 1938, the Laros "Dimensional" slip was developed, which fit any of nine body types. This was enhanced even further with the development of the patented Laros No-Ride slip in 1940. In the 1940s alone, over eight million Dimensional slips with no-ride technology were sold.

World War II harkened a pivot point for the company. In 1941, Laros sold off a significant amount of the silk weaving equipment. Up to this point, the majority of the raw silk the company used came from Japan. However, the company pivoted during this time to using synthetic materials, such as nylon and rayon. Additionally, the company expanded from producing just undergarments to also producing fragmentation bomb and flare parachutes, pajamas, uniforms, and Navy signal flags. During the second world war, over 100,000 of the fragmentation bomb parachutes were produced. The company received a commendation from the Ordnance Department for their quality product.

Unfortunately, post World War II was not ideal for the company. Two nylon products were on the market, woven and tricot, and Laros Company used woven. Unfortunately the nylon tricot was the superior of the two and products made with tricot significantly outsold the woven, leading to rocky times for the company.

However, the 1940s and 1950s did see an alternative product made by the Laros company. Russell Laros invested in a techqnie to convert sugar molecules into a structure comparable to human blood plasma. They originally established a Plasma Department in the Bethlehem Plant, and in 1943 opened a plant in Kingston for plasma and IVs. The product developed, "Plavolex," short for plasma volume expander, was a synthetic blood fortifier and exapnder. This led to a contract from the government to supply Plavolex during the Korean conflict.

However, after the contract ended, the company could not bounce back. After Russell Laros passed in 1955, the company was sold in three lots. First, the East Broad Street factory was sold to Sure-Fit. Second, the succeeding president of the company, John Kornet, bought the plasma business. Finally, after moving the textile business from the East Broad Street factory to a smaller location under the Hill-to-Hill Bridge, the remainder of the business was bought by Warner Brothers, a Connecticut-based textile firm, in 1957.


.25 Cubic Feet (1 slim legal box)

Language of Materials


Processing Information

Processing was completed in December 2019 and January 2020 by Melissa Nerino. The finding aid was created in January 2020.

Language of description
Script of description

Repository Details

Part of the Industrial Archives & Library Repository

18 West 4th Street
Bethlehem Pennsylvania 18015 USA