Browning is a yellow, brown or red discoloration due to degradation of cellulose in the presence of moisture. Cellulose is a material derived from plants that oxidizes or degrades with age producing a natural dye that causes this discoloration called “browning.” An excellent example of cellulosic browning is the yellow discoloration that occurs in a newspaper as it ages. A brown discoloration can also occur when there is incomplete rinsing of high pH detergent residues. Consumer spotters and previous cleanings using inappropriate products usually cause this problem.
Cellulosic fibers found in rug face yarns or backing materials are the source of browning. The more cellulosic material in a rug, the greater potential for browning exists. The age of the rug is also important because an older rug is more likely to brown. After wet cleaning, the potential for browning depends on the humidity, drying time, materials and age of the rug.
If browning does develop, it can generally be corrected by the experts at Oriental Rug Cleaning Co. as it is not always a permanent stain.