Do you ever wonder why some upholstery fabric and rugs stretch, shrink or ripple? If it is a natural fiber, the textile isn’t shrinking, it’s actually swelling due to the highly absorbent natural fiber backing yarns (wool, cotton, linen, ray- on, jute, etc.) when wet. Enlarged yarns require more space from the outer perimeter of the rug or fabric, thus drawing
it inward. There is virtually no shrinkage associated with synthetic fibers, however many textiles and rugs contain a combination of fiber types. Relaxation shrinkage occurs when tension is released, and yarns and backing materials attempt to revert to original dimensions. The irregular shape of some oriental rugs and edge rippling over time may be the result of relaxing shrinkage (stretching) from traffic and use. Stretching or growth is the opposite of shrinkage and infers that a fabric elongates, stretches or distorts. When we wet clean these items the fabric tension is relaxed and when dry they usually go back to their original condition. It isn’t unusual for a rug to shrink slightly – just as cotton and wool clothing does in even a cold water hand cleaning, since most rugs have cotton, jute or wool in their foundation.
In the weaving of fabric, each operation can add various amounts of tension to the fabric yarn. Most yarns that are stretched will return gradually to the original position unless they have been over stretched by heavy objects. Fortunately, many fibers used in textile fabrics have been pre-shrunk. And in most cases, rugs have been washed after woven. Rest assured, we are aware of this condition, but cannot always predict it will occur especially when cleaning hand-made or hand-woven items. Blocking a rug is a common solution for this problem.