The use of kenaf as a textile fiber for sacks spread to different countries of the Asian continent, such as China, Russia, Persia and - after the beginning of the World War II - to the American continent.

Indeed, it was the United States of America that, needing to find an alternative to the supply of sack fibers due to the impossibility of obtaining refueling of jute in consequence of the invasion of the monsoon basin of Asia by the Japanese armies, classified sack textile fibers as "strategic material" (*); as of 1942 - they began vast research into kenaf, at the beginning in collaboration with Cuba and later with Guatemala.

With the end of the war and with the return of jute fiber to the international markets, the Americans abandoned these programs which were continued for textile purposes by many countries of South and Central America, Africa (mainly by the French, for their colonial territories, and by the South Africans) and Australia.
But still today most of the existing selected varieties of kenaf natural fibers above all are due to the research carried on by the United States in the '40s.

(*) "Strategic and Critical Materials Stock Piling Act" and "Defense Production Act" of 1950.

Source: "Il kenaf, non solo una nuova materia prima cellulosica" - G. Mignoni