Research behind the exhibition
This exhibition is related to a research project studying the characteristics of cloth made for trade by the Hudson’s Bay Company and the East India Company.
The project also aims to test whether these characteristics match those of cloth on ethnographic artefacts. This project is called ‘Developing a Physico-chemical Test of British Wool Tradecloths to Identify their Presence in Ethnographic Artefacts’. It is being done by Morwena Stephens through the Arts and Humanities Research Board (AHRB) Research Centre for Textile Conservation and Textile Studies based at the University of Southampton. Some characteristics of cloths being analysed are shown below:
Table to show variables of the test for known examples of British wool tradecloth
|Characteristic analysed||Tools / tests|
|Fibre||Sheep breed (warp & weft)||Microscopy (by a specialist)|
|Yarns||Spun and ply characteristics (warp & weft)||Magnification: angle & direction of twist|
|Yarns||Diameter (warp & weft)||Microscopy and measurement|
|Cloth||Weave type||Visual observation|
|Cloth||Weave count (warp & weft)||Magnification and measurement|
|Cloth||Dimensions: width, thickness||Measurement|
|Selvedge||Fibre, colours, width, technique||Visual observation, fibre identification|
|Dye||Fibre/yarn/cloth, dyestuff||Dye analysis (by a specialist)|
As well as testing historic samples from archive and museum collections, information on broadcloth manufacture has been collected from accounts such as W. Partridge’s 1823 A Practical Treatise on Dying of Woollen, Cotton, and Skein Silk with the Manufacture of Broadcloth and Cassimere Including the Most Improved Methods of the West of England, and from dyers’ recipe books.
Many of the characteristics of the cloth can be identified by visual observation, sometimes using a microscope, and by measurement. Other tools are necessary to analyse the dye used as well as the mordant, or metal salt, that binds the dye to the fibre. High Performance Liquid Chromatography (HPLC) is used to analyse the dye in the samples. This technique relies on separation of organic components of dyestuff extracted from a small sample of the textile. The quantity of the different components can then be compared with reference samples for known dyestuffs to identify the dye used in the historic textile. The inorganic mordant, a metal salt such as alum or a tin or a chrome based salt, can be detected by looking at the X-ray emission spectrum in a scanning electron microscope. Each metal has its own characteristic spectrum, enabling the mordant used to be identified.