A balanced strand includes a fibrous core about which load bearing fibers are twisted. The fibrous core has an elongation factor of at least 10% and comprises approximately up to 30% of the material volume of the strand. The load bearing fibers have an elongation factor less than the fibrous core...http://www.google.es/patents/US5852926?utm_source=gb-gplus-sharePatente US5852926 - Balanced strand cordage
