Sashiko is a plain-stitch embroidery used as a
decorative strengthener, primarily on plain indigo-dyed cloth. For
warmth, two or more layers of cloth were often attached in a form of
quilting using small sashiko stitching. Modern-day versions
of sashiko are seen in the reinforcing in judo and kendo uniforms and on some
Originally sashiko was applied to the corners of furoshiki, the
wrapping cloths used to carry things, in lieu of bags or suitcases. Extremely large furoshiki, four or five feet square, were used to carry large, heavy loads, and the corners that are tied, around the materials transported or around the bearer, require reinforcement to hold their shape and not tear. Sashiko was stitched on to them, sometimes in two or even four different patterns on a single furoshiki. Tabi, the split socks worn with zori or geta thong sandals, were also reinforced with sashiko, as were drawstring bags. Work clothes which receive wear over the shoulders and across the chest, where loads rest on or ropes rub against the worker, were also reinforced with sashiko, often simple running stitches, but occasionally in decorative lozenge patterns on separate strips of cloth which were then applied to the garment. This beautiful handwork thus received the most wear, and is often in worse condition than the rest of the clothing, as can be seen in some of the vests on this site.
Sashiko is used in many patterns, some of them representational in a stylized way, such as tortoise shell, waves, and lozenges.