 Latch hook was invented in the nineteenth century with the latch needle, in the twentieth century the latch needle underwent numerous variations including the hand tool used by artisans and crafters to produce latch hook rugs.While rug hooking uses a base fabric of burlap or hessian, latch hooking uses specially woven rug canvas.Rug canvases range from 3.3 holes per inch (hpi) to 5 hpi.