Two characteristics of carpet are primary considerations when choosing a carpet: the type of natural or synthetic fiber used in the construction, and the pile—how the loops of fiber are attached to the carpet backing. These characteristics determine the comfort of the carpet, how it feels underfoot, and its wear characteristics. Here are the common carpet fibers and pile options to consider. Pure wool carpet is made with no chemicals or additives, which makes it an excellent choice for those with allergies or sensitivities to chemicals. But as a natural material, wool can be prone to damage from mold and mildew, which feed on organic substances. Wool is therefore not a good choice for areas where high humidity and moisture are an issue. Loop pile carpet comes in variations, such as level loop, where the fiber loops are all the same length, and patterned loops, where the loops are different heights. It is also possible for a carpet to have cut-and-loop construction, where some fibers are cut and others are looped. A particular type of loop-pile carpeting is the sisal carpet, in which loops of different colors, and sometimes different heights, are arranged in rows, to produce a textured, patterned surface.
Caution: The loops of uncut pile are not only less soft and padded than cut-pile fibers, but experts warn how they can also be a snagging hazard, particularly for pets or small children.
On the downside, cut pile makes it easier to see footmarks and vacuum trails. This tendency can be reduced by the twist of the fibers. The individual fibers contain a twist that helps the carpet stand up against matting and crushing. The heavier the twist, the more resistant the carpet will be to matting. Heavy twist also helps create texture that hides wear and dirt. Although much more popular than loop-pile carpet, cut-pile carpets are not as durable and will need to be replaced more often. They come in several variations, including shag carpet, a term which refers to a deep pile carpet featuring long-haired fibers that are soft to touch. Shag carpet is now relatively rare, but other specialty cut-pile forms (described below) are quite popular and used for particular effects.
