Medieval activity was encountered in almost all the trenches, much of which could be attributed to the presence of Dyers and bleachers of worsted cloth known to have operated from the site from the 1200s. The lost medieval lanes which once crossed the site down to the river have names associated with this industry, such as Bleckstershole (Bleachers’ hole) and Fullershole, once being located off Letesterersrow (Dyers’ Row) and Shererow (Shearers’ Row).
The site was a focus for a processing industry fundamental to the city’s medieval textile production. These processes involved wet processing both to bleach cloth using urine and lye solutions and to fix cloth with dye using hot water and urine or other dye fixing agents. Fullers also used lye pits to process woollen cloth. Evidence for the processes of bleaching, dying and fulling was identified across the site in the form of large numbers of intercutting 13th to 14th century pits utilised for wet processing, with some of the clay-lined pits utilised as hearths.