Grow your own colours...
Dyes derived from coal and oil have only been available since the middle of the 19th century. For thousands of years before that, people added colour to their fabrics using dyes extracted from plants and other natural sources. Now, practically all the dyes used commercially are made from fossil fuel resources.
Fortunately, some third world communities, as well as craft dyers, have kept alive the tradition of extracting dyes from plants, and with the current move to find renewable resources, commercial interest in plant dyes is higher than at any time since synthetic dyes were first discovered.
Dyeing with plants is an absorbing and interesting hobby, and even more so when you grow the dye plants yourself. There are so many possible combinations of plant, mordant, method and fibre that you have endless opportunities to experiment and develop your own "recipes". You may become interested in researching and reproducing historical methods, or perhaps applying scientific principles to the dyeing process.
If you spin, weave, make felt, or practise any other fibre craft, you will find that dyeing with plants is a worthwhile extension of your craft, offering another way to make your products unique.
I hope you will find these pages interesting and useful, and that, if you have never tried plant dyes, you will be spurred to have a go.