Embroidery done using crewel wool, a two ply wool yarn. It uses a wide variety of stitches and grounds, but if I say 'crewel' it's done with crewel wool. Crewel stitches are not over specific numbers of threads, they require the embroiderer to determine size, shape and placement.
Crewel is a hand embroidery technique from Kashmir in which fine, loosely twisted two-ply yarn is chain-stitched on cotton cloth. Imperfections, color variations, irregularities, natural black specks, dye marks, and dirt spots are characteristics that label it as genuine. These fabrics are handwoven by natives in India, and the beauty of the cloth is in its natural, homespun appearance.
A loosely twisted wool yarn used in embroidery that results in a raised textural design. Crewelwork was popular in England under King James and came to America with the colonists. Today the floral crewel motifs (based on The Tree of Life) are created from a variety of yarns and materials and grace everything from window valances to pillows to sofas.