Birch Bark is capable of dyeing fibres in shades ranging from creamy yellow and beige through to soft pink and pale tan, depending on the fibre, mordants and dyeing method used. The colours produced by birch bark are characteristically soft and variable, and these natural variations are part of the unique appeal of natural dyeing. Rich in natural tannins, birch bark will readily bond with fibres without the use of a mordant, although mordants such as Alum may be used to enhance colours and improve wash-fastness and lightfastness.
Birch bark dyes protein fibres such as wool and silk particularly well. Cotton and other cellulose fibres do not readily bond with natural colourants and are traditionally treated with tannin before mordanting with Alum. As birch bark itself contains natural tannins, an additional tannin treatment is often unnecessary, although some dyers may choose to use Oak Galls or tannic acid to enhance colour depth and fastness.
Birch bark dye baths are naturally slightly acidic. If desired, the pH can be adjusted towards neutral with a small quantity of dissolved Soda Ash, which may help preserve the softer pink and salmon tones.
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?
