Sashiko (刺し子) is a versatile Japanese stitching and embroidery technique primarily used to mend, reinforce, and embellish garments. In the past, the women of rural farming communities practiced this simple running stitch using white thread on indigo-dyed fabrics like cotton and hemp. Over time, sashiko has evolved from a frugal necessity to a decorative stitching style. 

Sashiko embroidery uses running stitches to create geometric patterns. It involves loading multiple stitches onto a large-eyed needle and securing the thread with back stitches at the beginning and end instead of knots. The style is known for its striking appearance, often with white thread on dark indigo fabric, though modern variations use various colors and fabrics.