Cutch powder comes from the heartwood of the cutch tree Acacia catechu and contains tannin. When dyeing protein fibres with alum mordant the dye has excellent light fastness and produces rich tones of brown, on cotton and other cellulose fibres, cutch produces lighter shades of brown to tan. An after treatment in a dilute solution of ferrous sulphate (Iron mordant), known as saddening, cutch will produce darker shades of brown to black and a khaki brown with copper mordant. An orange tone can be achieved when Titanium Oxalate is used as the after-soak.
Important Natural Dyeing Tips
Most natural fibres can be dyed using natural dyes. Some natural dyes can be used without a mordant, while others benefit from mordanting to improve colourfastness and help achieve particular shades.
Wool and silk are commonly mordanted with alum, while cellulose fibres such as cotton and linen can be mordanted using aluminium lactate. Another method is to prepare cellulose fibres with a tannin solution followed by an alum mordant. This age-old technique can sometimes affect the final colour of the natural dye through the colour absorbed during the tannin soak – a side effect that may be desirable.
Another use of mordants is to modify the colour using an after-treatment of iron, copper or tin mordant; these will each shift the original natural dye colour. Whether you’re dyeing wool, silk, cotton or linen, natural dyes offer a wonderfully varied range of colours and effects, and many factors can affect the results.
You can find answers to the following questions in our Blog post A Practical Guide to Natural Dyeing – How to Get the Best from Natural Dyes:
- Why do I need a mordant and how do mordants work?
- What is the method for mordanting protein fibres?
- What is the method for mordanting cellulose fibres?
- How much natural dye should I use?
- What colours will I get from my natural dyes?
- How do I modify or shift colours from natural dyes?
