Reproducing colourful woven bands from the Iron Age salt mine of Hallstatt in Austria: An interdisciplinary approach to acquire knowledge of prehistoric dyeing technology

Textiles from the Bronze Age and Iron Age have been preserved for more than 3000 years in the salt mine of Hallstatt, Austria. Copper originating from prehistoric mining tools made of bronze has probably altered the colour of many of the textiles. Three woven bands from the Iron Age were chosen for reproductions in order to show how they might originally have looked, and to acquire knowledge of prehistoric dyeing technology. Dyeing techniques documented in historical, ethnographic, and experimental archaeological literature were analysed. Fibre, dye and element analyses of the prehistoric bands formed the basis for the experimental development of dyeing methods using woad (Isatis tinctoria L.), weld (Reseda luteola L.) and scentless chamomile (Tripleurospermum inodorum (L.) Sch. Bip.). The hand spun yarns were woven with rep band and tablet weaving techniques. Each band was successfully reconstructed in two possible colour variants. The light fastness of the dyed woollen yarns ranges between level 3 and 6 and matches everyday requirements today. Element and dye analyses and a post-mordanting experiment with copper acetate explain today's colours of the woven bands. A detailed picture of conceivable dyeing techniques in the Hallstatt Culture is provided, concerning the handling of textile material during dyeing, woad processing and dyeing procedures, mordanting techniques, and the tools and resources required. Dyeing with natural dyes is an ancient cultural technology that is simple in terms of equipment and resources, but sophisticated in terms of the knowledge required. It fully reflects the comprehensive knowledge prehistoric people had of the chemical properties of natural substances, the effect of temperature on (bio)chemical processes, and the ability to control and manage these processes. In central Europe, the beginning of this knowledge dates back to Bronze Age, the 2nd millennium BC, as proven by the textile finds in Hallstatt.