Piled stitches are those which are formed by loops of thread which can be left as loops or cut to form a texture like the surface of a carpet.
They are worked by leaving loops of thread on the surface which are then anchored in place with small stitches. The loops can be kept of an even length by wrapping them around a gauge (a narrow implement laid along the stitch’s path). Gauges (also known as a mesh) were popular in the 19th century and could be made from metal, wood or bone and varied in size from a sixteenth of an inch to 2 or even 3 inches. Some had a groove which served as a guide for the scissors if the loops were to be cut, and some of the metal versions had a sharp edge which was used to cut the thread as it was removed. Knitting or crochet needles, dowel or narrow rulers can all be used as improvised gauges. The pile was often trimmed to follow the contours of a design, especially within Berlin wool work.
Piled stitches are often worked on canvas, but can also be worked as a surface stitch. They are known collectively as velvet or plush stitches, or as Turkey work (named for their origins in Turkish carpet-making).