A dobby loom, or dobbie loom, is a type of floor loom that controls all the warp threads using a device called a dobby.Dobbies can produce more complex fabric designs than tappet looms but are limited in comparison to Jacquard looms. Dobby looms first appeared around 1843, roughly 40 years after Joseph Marie Jacquard invented the Jacquard device that can be mounted atop a loom to lift the individual heddles and warp threads.The word dobby is a corruption of "draw boy," which refers to the weaver's helpers who used to control the warp thread by pulling on draw threads. A dobby loom is an alternative to a treadle loom. Both are floor looms in which every warp thread on the loom is attached to a single shaft using a device called a heddle. A shaft is sometimes known as a harness. Each shaft controls a set of threads. Raising or lowering several shafts at the same time gives a huge variety of possible sheds (gaps) through which the shuttle containing the weft thread can be thrown.