a yellow, red or brownish discolouration formed when cellulose, particularly jute is degraded in the presence of moisture. It can result from over-wetting cellulose, especially with high pH for long periods resulting in the dissolved cellulose components wicking to the surface of the carpet where they stay after the water has evaporated.
browning is usually corrected with mild solution of acetic acid, citric acid or a mild solution hydrogen peroxide (3%)
upholstery cleaning in