By 1810, brightly coloured and embroidered silks were as popular as white cotton and muslin for women's evening dresses. John Heathcote's bobbinet machine, patented in 1809, enabled fine net to be easily produced in wide widths for dresses, which could be hand-embroidered to achieve individual and attractive effects. Net dresses were worn with underdresses of plain silk, sometimes white, or in a matching colour. Chenille (French for caterpillar) is a type of thick thread made by a weaving process. Cotton or silk is woven into a length of cloth which is then cut into very narrow strips, the severed weft threads creating the tufts which give the yarn its velvety texture. The dense colour of chenille thread creates a contrasting effect with the ground fabric. Fashion leaders such as Empress Josephine, Napoleon's first wife, helped to popularise dresses of machine net, or 'tulle', which was also produced in France. She owned many machine-made net dresses embroidered with silver or gold metal thread and spangles for formal court occasions.