Without a visually apparent alteration of the silk, anionic surfactants like Orvus paste or Orvus Liquid are adsorbed onto the fiber of silk. Fabric composition is affected. Comparisons of adsorption for different fibers will be reviewed, especially with nonionic and anionic surfactant solutions. The importance of this data in developing treatment programmes for silk and mixed fibre textiles (embroideries, tapestries) is discussed. The purpose of this presentation is to provide the practicing textiles conservator with data from research and from experimental confirmation.