Sashiko embroidery has been used in Japan for centuries, dating back to the Edo era of the 1600s to the 1800s. The Japanese word sashiko means "little stabs" and refers to the small stitches used in this form of needlework.
This style of embroidery and the "sashiko stitch" was used to reinforce or repair worn fabric or tears with patches, making the darned piece ultimately stronger and warmer.
-- 
--