Rajasthan is a large state in northern India known for its fine quality wool. Jaipur, Bikaner and Ajmer are Rajasthan's main rug-weaving districts. The modern regional carpet industry began in earnest in the 19th century when rug weaving was introduced as a prison craft but has a much longer history in the area. Royal patronage ensured that palaces were furnished with fine Mughal carpets for centuries. Indian rug weavers initially wove in the "Persian style" fusing the patterns of "city rugs" from famed Persian carpet cities with their own ideas to create patterns recognized as Indo-Herati, Indo-Kerman, and Indo-Persian. Rug patterns were also influenced by Afghan, Bukhara, and tribal geometric rugs. Bikaner and Ajmer are known for fine hand-knotted rugs inspired by Mughal designs. Rajasthani motifs include rosettes, geometrics, thin serrated leaves, flowers, and the classic boteh (a teardrop shape known in the West as paisley). Rugs were generally woven on stationary, vertical looms with a cartoon of the pattern near the loom to guide the weavers. Rajasthani rugs usually include three passes of weft between each row of knots. The first and third row are shot straight through the shed while the middle row "meanders" over and under the warps on both levels. Most rugs are wool but the middle weft in "three pass" wefts is often silk. The suppleness of silk allows for tighter packing of the weft rows with the beater. The asymmetrical (open on one side) Persian knot is standard. It is tied to a warp, passes over the next, ties to the next and so on across the width of the rug.