The word teasing is derived from the teasel (or teazel) plant, Dipsacus sativus. The teasel has a thistle-like seed head, with sharp spikes surrounding the seed casings. Since the Middle Ages, Europeans have used the dried seed heads of the teasel plant to raise the nap on woolen cloth, and in the eighteenth-century the plant was introduced to the American colonies. Teasing wool creates a soft, almost furry texture on one side of the cloth. Baize, the cloth traditionally used to cover billiard and card tables, is a classic example of wool that has been teased.
The object below, from the storage collections of the Museum of Early Trades and Crafts, is an example of a teasel cross, or, as it was also called, a teasel hand. Some of the teasel seed heads are missing from this example: you can see the holes where they would once have fitted, creating a densely spiky surface across the entire width of the top.
The following image, an English print, shows how the teasel hands were used in raising the nap on the wool. The cloth was stretched over a frame, and hand workers methodically brushed the teasel hands across the surface of the wool, working from one end to the other, until the soft wool fibers were loosened and a shaggy surface hid and softened the weave. Since the nap did not raise evenly, after teasing the wool, another worker had to go back over the cloth and shear the fibers close to the surface so that the finished product had an even, velvety texture.
According to Anna Benson, the English developed a machine form of the teasel frame, the teasel gig, (see below) as early as the sixteenth century, but Parliament forbade its use in order to protect the jobs of hand workers. By the early nineteenth-century, however, the teasel gig had been incorporated into the technology of most English woolen mills.
American wool manufacturing lagged behind English precedents, but it is impossible to say whether our teasel frame is European or American. It is one of those extremely basic tools that lacks regional or other distinguishing characteristics to mark its origins.
But, wherever it may have been used, it seems quite possible that the teasel seed heads themselves were grown in this country. Across New York and New England, nineteenth-century farmers grew fields of teasels alongside crops of corn, oats, potatoes, vegetables and tobacco. It has since naturalized as a weed, and it is surprising to discover how much care went into the growing of teasel plants. After preparing the soil and sowing the teasel plants, the plants had to be thinned to about one foot apart. Fields of teasels had to be diligently weeded and fed. The plants didn’t develop seed heads until their second year. The farmer harvested the seed heads as they turned brown in the autumn, and then dried them thoroughly in the sun. A farmer growing teasels could expect a yield of 150,000– 50,000 heads to the acre. Since teasel heads wore out quite quickly with use, and wool manufacturers needed constant supplies of replacements, growing teasels could be quite profitable.
Modern wool manufacturers use fine combs with steel wires to raise the fibers for baize and other teased fabrics. It is universally admitted, however, that there is still no substitute for teasel heads in producing the finest cloth.
 “Two Teasels: The Medieval Garden Enclosed,” Metropolitan Museum of Art, The Cloisters Blog. http://blog.metmuseum.org/cloistersgardens/2009/10/16/two-teasels/
 “Baize and Bay(e)s,” Pegs and Tails Blog, http://pegsandtails.wordpress.com/2012/02/11/baize-andbayes/
 Anna P. Benson, Textile Machines (Princes Risborough, UK, 2002),7.
 “Teazels,” Connecticut Historical Society Manuscripts Blog, http://manuscripts.wordpress.com/?s=teasel