This filling stitch consists of parallel closely worked rows of a long version of double running stitch.  The stitches can be worked in a multitude of layouts: lined up with each other; offset to form diagonal lines; bricked; or stitched to form more complex patterns.  When worked carefully, the reverse of the fabric is identical to the front.

The stitch is commonly worked along the grain of the fabric, but it can be worked diagonally, or to follow the contours of a design.

The versatile nature of this stitch is supported by the wide variety of embroidery traditions which use it.  By the time of the 18th century, double darning was widely used across the eastern parts of Europe and much of Asia.  The Victoria and Albert Museum, London has a large number of artefacts, including a 17th century Turkish turban cover, an Azerbhaijani panel from the 19th century and a pictorial Rumal (coverlet) from 18th century Punjab.