Owing to the relatively cheap nature of white cotton thread and the abundant nature of cheap, indigo-dyed blue cloth in historical Japan, sashiko has a distinctive appearance of white-on-blue embroidery, though some decorative pieces may also use red thread.
Though most sashiko utilises only a plain running stitch technique, sashiko is commonly used to create decorative and repeated embroidered patterns, and may be used for purely decorative purposes, such as in the creation of quilts and embroidery samplers.
Common sashiko motifs are waves, mountains, bamboo, arrow feathers, shippō-tsunagi, pampas grass and interlocking geometric shapes, amongst others.
Many sashiko patterns were derived from Chinese designs, but just as many were developed by native Japanese embroiderers; for example, the style known as kogin-zashi, which generally consists of diamond-shaped patterns in horizontal rows, is a distinctive variety of sashiko that was developed in Aomori Prefecture.
Sashiko designs typically derive from nature, with some, considered to hold symbolism, seen particularly on garments such as the coats of fishermen.