After a rug has gone through the weaving and knotting process, it must be trimmed to its predetermined length. The pile – meaning the thickness of the rug – is made up of many short, individual pieces of yarn tied around two warp strands.
These pieces can vary in length, making the rug slightly uneven. Before a rug can be placed on the market, it must go through a very intensive clipping process that ends in a wash to remove dirt and other debris from the material.
Two Steps in the Clipping Process
In general, Oriental rugs' pile is trimmed on two different occasions. The initial clipping is performed by a weaver right before the knotting process begins. This clipping is performed to make the process of knotting the rug slightly easier.
The second clipping is left to someone very skilled in clipping precision with a steady hand and an eye for detail. Typically, this job is left to a hired specialist, but in nomadic or traveling tribes, the most skilled weaver of the group takes on this responsibility.
There are several influencing factors considered when determining a rug's pile length. The most important influencer is the rug's weaving group and the stylistic traditions by which the group abides. Some weaving groups and cultures prefer to have longer, fleecier pile; other cultures prefer to have close-cropped piles. Examining pile length can also be a distinguishing factor when determining where a rug's country of origin.
Another highly influential factor in determining the length of the pile is the design. Although longer-pile rugs are softer and sometimes more pleasant to sit on than shorter-pile rugs, an intricate design can easily be lost in longer-pile rugs. The finer the knot, the more intricate the design, which means that the rug will have a shorter pile.
Otherwise known as incising, embossing is the process of trimming the pile to different lengths in order to accentuate specific designs in the rug. This process is very time-consuming and requires a large amount of skill and precision, as it is easy to incorrectly trim a pattern, ruining months of weaving work.
This design style is typically used in Chinese and some Indian or Anatolian rugs. When finished, an embossed rug will combine several different lengths. Because embossing is so challenging, it is usually only applied to bold, thick outlines, which limits its use to large, simple designs. When this is not possible, the design is typically accentuated by a different material – usually silk – that creates a natural contrast to the main material of the rug.