Frosting is a condition of color change in textiles, most often occurring with fabrics and upholstery, also result in appearance changes on rugs and carpeting. It is caused by preferential abrasion or a wearing away of colored fibers and dye from the fabric or pile surface. This occurs primarily in those areas where use, wear and abrasion are most concentrated. In upholstery, it could be on the front edges, side and top of the seat cushion, or arm areas. In draperies, it may be worn sections at the hem. In carpet or rugs, it would be the wearing away of surface pile that then reveals a slightly different or more original pile color underneath.

To textile scientists this condition is known as "frosting," most likely because the resulting worn away color is usually lighter, whiter or "frosted" compared to the original. But it could result in other color changes as well. The analogy to frosting or whitening is best known and understood by analogy with denim jeans. These fabrics are typically woven with a thin blue warp yarn, and a thicker white filling, weft or woof yarn.. The fabric is a 2/1 or uneven twill weave. When new, the blue warp tends to predominate on the surface and hide or cover the white filling. But as wear progresses, the blue surface yarns are abraded and worn away so that the fabric becomes increasingly light white or "frosted" in these main wear areas. This same condition can occur with textile furnishings such as upholstery fabrics, where concentrated use and wear will abrade away the surface fibers and possibly also rub off some of the dyed fabric surface.. This latter condition is known as "crocking.." Whether the cause of color change is primarily abrasive wear known as frosting, or rubbing off of the dye known as crocking, the resultant color change is a permanent condition. It is not, however, the fault or doing of a professional cleaning, as conditions creating the color change in the wear areas had already occurred.

There are times when this slowly developing color change or lightened areas of the fabric may seem more noticeable after a professional cleaning. But this is the result of removing surface soiling and greasy wear stains during cleaning, only to reveal the lightened areas of worn fabric underneath. The actual condition had existed, however, prior to the cleaning. Also, worn rug or carpet areas can reveal more of the backing or foundation underneath, at times seen as "grinning" up through the pile and showing a lighter or different color. So, too, can white knots, normally buried in the carpet pile or obscured by soil and dirt, become more noticeable after a thorough rug or carpet cleaning, These, too, are conditions of abrasive pile wear during ordinary use, and not the result of rug or carpet cleaning.. The professional cleaner may consider, at the wish of the customer, coloring in the white knots or worn pile areas to better match the surrounding pile color. It must be recognized, however, that this cosmetic coloring is temporary and the underlying color changes will eventually return.