Many plants produce stable colourations or pigments which have been used as dyes in the past. Their use decreased as organic dyes based on coal and other fossil feedstock became available at lower cost. This project looks at the feasibility of reversing this trend and providing high quality natural dyes from plants, creating new opportunities for both farmers and the fabric industry, in line with the current consumer trends towards natural products. Initially 4 possibilities were investigated, madder for red and woad for blue, as well as weld and golden rod for yellow. In addition, a wide range of other species have been looked at. Most gave good dyeing performance. However, problems remain to be solved in production of planting material, yield and competition against low cost imports.
In addition to these species, more potential dye plants were cultivated and investigated in regard to their mass yield and dyeing abilities. The following aspects were noted: growth, mass yield, possibilities of mechanical seeding and harvesting of seeds. Some of them have a high yield potential. Preliminary dyeing experiments suggest there are species which may have higher dye contents and/or greater dye strength than Reseda or Solidago and with a shade similar to the latter. These include Serratula tinctoria, Chrysanthemum vulgare, Centaurea jacea and Anthemis tinctoria. The dye producing plants investigated are mainly wild types. Nevertheless, many of them can be adapted to modern cultivation practices for industrial use at low costs and at a high yield of useful products. The trials on textiles were so promising that it is anticipated that the use of such dyes would occur on an industrial basis in the near future. Attempts to develop an ecological acceptable method for waste water treatment were successful. Good results for the purification of waste water were obtained with activated carbon.