Since the cleaning of histortic textiles is a crucial part of the textile conservator's work, it was decided to investigate washing solutions. This paper focuses on the soil anti-redeposition agent sodium carboxymethyl cellulose (CMC). The problems and theory of soil redeposition, the increased hazards involved in using hard water for washing, and the properties of cmc, precede recommendations for its use (including the importance of choosing the right grade). Three ways are recommended to minimize the problem of soil redeposition in the cleaning of historic textiles.