Dyeing plants screening: an approach to combine past heritage and present development

The paper reports an investigation of the colouring properties of 43 dyeing plants chosen for their widespread use in previous centuries. Colorimetric analysis showed that the principal colours on different fabric supports were yellow and mostly unsaturated. The nature of the support fibres investigated, protein‐ or cellulose‐based, was shown to play an important role in the perceived colours. Phytochemical analysis confirmed that yellow‐orange shades could be attributed to flavonoids and that red colours were due to anthraquinones. Colours from plants that contain anthocyanins varied from blue‐violet through reddish depending on the structure of the anthocyanins in the individual plants. Colour fastness was determined by applying standard test methods. Fastness to light appeared to be inadequate for industrial applications for most samples, but it seems that this could be improved by certain molecular associations. On the other hand, colour fastness to water was satisfactory.