Consider the range of colours you can create: rich bronze from onion skins, dusty pinks from avocado rind and pit, purple from red cabbage and yellow from carrot tops. Lengths of yellow onion-dyed linen, with soft edges, add a touch of romantic style. I love the rustic look of linen, but you can try any natural fabrics for making runners and napkins. You can also make full tablecloths or bed throws.
Onion skins. You’ll need 100% of the weight of the washed, scoured and dried fabric in skins – for 500g fabric, you need 500g dry onion skins.
Irish linen (plant fibre). You can also use organic cotton, which would give a similar rustic finish. Silk (animal fibre) can give a more romantic look.
Most dyes need a mordant to fix the colour to the fibre. Plant fibres can be mordanted with a plant-based mordant such as tannic acid (extracted from oak galls, as well as acorns, chestnuts and oak bark) or mineral based mordants such as Iron and alum. Animal fibres can by mordanted similarly with rhubarb leaf or alum.
MAKING A DYE BATH
Weigh the fibre after it’s been washed, scoured and dried. For a deep shade, use 50% of the weight of the fibre in the skin – for example, for 400g fibre, use 200g onion. Onion skins are super-easy and quick to dye with. No need to chop them, simply put them in the dye pot and pour in enough water to allow the fibre to move freely. Bring to a simmer, and simmer for 30 minutes. The colour of the water will change and deepen quite quickly. Strain out the onion skins and use the liquid as the dye bath.