EXARC Journal (Nov 2021)
Before They Dyed. Mordants and Assists in the Textile Dyeing Process in Anglo-Saxon and Anglo-Scandinavian Britain: An Experimental Approach
Abstract
The experiment aimed to investigate certain aspects of the textile dyeing process in Anglo-Scandinavian and Anglo-Saxon Britain: substances known as mordants and assists. This aspect of the dyeing process is often omitted by researchers, who mostly focus on dyestuff as a source of colour. Mordants and assists deserve wider research, however, as they play a great part in the dyeing process and can radically change the outcome. They are derived from different sources, both mineral and organic, and are added during the dyeing process to influence the final result, mostly in aspects of shade and/or fastness. For the experiment, madder (Rubia tinctorum) was chosen as a dyestuff, as it was one of the most popular dyeing plants in Britain before the Norman Conquest. The fibre of choice used for the experiment was wool spun from the Shetland sheep fleece. Investigation of several sources, written, archaeological and ethnographic, allowed compilation of a list of 16 mordants and assists which were available to use in Early Medieval Britain during the pre-Conquest period. One untreated sample was prepared as a comparison. During and after dyeing, quantitative and qualitative data were collected about pH of the solution, final colour (measured with a colourimeter) and lightfastness (measured with a Blue Wool Scale). A wide range of colours was obtained, and it was found that, in general, adding mordants/assists improved lightfastness.
