Types of Rugs
There are many varieties of construction that define rug types and characteristics. Flatweave, needlepoint, hand-knotted, hand-tufted, hand-hooked, and machine-made are just some of the many classifications.
A hand-knotted rug is the type described above, with fine threads of colored yarn that are hand-knotted onto a warp/weft backing and then sheared to create a pile. There are a variety of actual knot styles, among which are Persian and Turkish knots. (see figure 2, right) A flat weave rug (figure 3,below ) is constructed without a pile. Here, colored weft yarns are woven through the warps to create the pattern. There are numerous varieties of flatweaves: kilims, dhurries, and soumaks, are just a few. Needlepoint is another type of flatweave that is created by the weaving of the colored yarns through a pre-made scrim, or grid-like backing. Aubussons and Savonneries, are much like needlepoint in appearance, but are created by the weaving of thread through a warp/weft construction. This technique is considered the most refined and precise form of flatweave rug-making. Interestingly, the terms Savonnerie and Aubusson have today become largely generic terms for certain French floral motifs of rugs in virtually any construction (e.g., a hand-knotted ?Aubusson?). The word Savonnerie means soap factory, and recalls the original function of the building where Louis XIII set up the first royal school for rug weavers. The king created this school as much for his own love of the carpets and fine furnishings as he did to encourage French manufacture and economic growth. The designation "Aubusson" refers to the province in France where this distinct weaving style developed. Hand-tufted rugs and hand-hooked rugs (figure 4, below right) are produced in much the same way. A tufting gun that works much like an oversize sewing needle is used to push and pull threads of yarn through a scrim — a pre-woven grid foundation. With a hooked rug, the loops of yarn are left intact to form a characteristically ?knobby? pile. In a tufted rug, the tops of loops are sheared to expose the thread ends for a softer and plusher pile.
Machine-made rugs are woven on mechanical looms. There are numerous types of mechanical looms, each with specific capacities as to the type of designs and textures it can create. In recent years, continuing advances in technology and product innovation have greatly expanded the fashion and quality range of this category.
From: http://www.nourison.com/NU/6types.asp