In recent years a large quantity of leather has been excavated at a number of sites in London. In 1983 alone, over 1,000 objects were treated by the Conservation Department of the Museum of London. This has provided ample opportunity to develop methods for the treatment of leather in bulk without compromising standards. This paper describes the procedures now employed. In addition, the opportunity has been taken to review some aspects of freeze-drying treatments carried on three to four years ago and previously published and to report on further investigation into the effects of glycerol as a plasticizing agent. See also AATA 19-1948.