"Woolen sails for replica ships start with the roundup on Jens Jakobsoy island of freerange sheep belonging to an ancient Norwegian breed. Per Johnson and his family pull the wool by hand—strong outer hair for the warp and downy inner wool for the weft. Tar and fat are added to the woven fabric to create water-resistant, wind-tight square sails like those carved on Viking picture stones."
—From "In Search of Vikings," May 2000, National Geographic magazine