I am fascinated by how the sombre lichens that grow on the rocks in Wester Ross can be used as dyestuff to produce wonderful colours. Although it is now lost in the mists of my failing memory I probably was lured into the Highland Guild by a natural dyeing workshop, as well as a need to improve my spinning. Workshops have focused on woad, indigo and mushrooms but lichens are freely available where I live and I have enjoyed exploring their properties. Sadly I tend to have a relaxed “crofters botch” attitude rather than methodical recording for my experiments.
To compensate for my inability to pass on accurate details of how I have achieved wonderful deep purples and bright oranges I thought I should draw together some factual information on the lichens. This effort was also motivated by a request to supply some lichens to a member of the Hampshire Guild. Lichens are locally common but slow growing and I was reassured by a local mycologists who said preserving the dye tradition was important. It therefore seemed acceptable to send a small parcel south and hope that they would produce some good colours which might be completely different with their water and fleeces. I could not ethically supply lichens commercially and I feel that using these lichens outside their “terroir” is somehow inappropriate.
Researching these lichens dyes showed there was some conflicting information and additional confusion from the Gaelic name “crottle” being used as a term for a variety of lichens. I have tried to clarify this. However I think that similar looking lichens can yield different colours and so a mixed batch could produce variations in the resulting dyes. There seem to be so many variables that consistency when dealing with small amounts might be impossible but experimenting is fun.
Lichens are not always easy to identify accurately but their location is usually a good indicator. The two main groups found growing on rocks in the West Highlands are the crustose, white Orchil lichens, which give reds and purples after soaking in ammonia, and the more leafy Parmelias which can be used without any mordant for orange browns.
Historically it seems that Crottle was used as a general term to identify lichens as dye plants and the name Crottle has been applied to different lichens. Some of these, notably Ochrolechia tartarea ( Cudbear lichen) and Ochrolechia parella ( Crab eye lichen), were collected for commercial processing to produce red, blue and purple dyes. These are sometimes referred to as Light Crottle as they are paler than the lichens that were used to produce the orange brown dye. The Black Crottle is Parmelia omphalodes which gives an orange brown fast colour with a distinctive smell. Parmelia saxatilis is paler but also gives an orange brown as does Anaptychia fusca.
The Orchil dyes can be traced back to around 1500 BC as a source of purple dye in the Mediterranean. In Scotland they are well documented from the 16th century. They include Ochrolechia tartarea and Ochrolechia parella which may be referred to as cork, arkill, corcir and korkalett. They were fermented in ammonia, usually stale urine, and then either used immediately or mixed with lime and formed into balls for storage. Their commercial potential was recognised as a means of substituting for the imported dyes from the Mediterranean. The Cudbear manufacturing operation was established in 1758, originally in Leith and later in Glasgow. It was said that only Gaelic speakers were employed to keep the process secret. The industry boomed, bringing huge benefits to the Highlands and Islands, as wars disrupted imports but the most easily accessible native stocks were quickly depleted. The wars then led to labour shortages so the company had to look beyond the Highlands and both the market for and the use of lichens dwindled.
Ochrolechia tartarea can give an Imperial purple.To test that you have the right lichen a drop of plain bleach should turn red on the crusty white surface. Other lichens will not have this reaction and may produce other colours. Luxury bleach brands which may be scented may not produce a reaction. Place the lichen in a jar and cover with an ammonia solution and put on a lid. The soaking liquid should turn purple in a few days and continue to deepen over a period of weeks. To dye with Orchil or Cudbear simply simmer the wool in the liquid . The sensitivity of ochrolechia to acid enabled it to be used for litmus paper as it will turn red with acid and blue with alkali. This property can be used to vary the dye colour.
The quality of the water and the pot used will affect the colour as will any changes in the acidity or using alum. Traditionally an iron pot would have been used. various factors in harvesting the lichens have additional effects: the area that the lichen is harvested from, the time of year and the weather. Different books recommend different seasons for collecting. In Shetland it was thought the best crottle colour came from lichens collected in August while the orchils, the korkalett dyes, should be gathered in late spring or early summer. Flora Celtica recommends gathering crottle after rain when it will come away more easily. Lichens growing closer to the sea were thought to be the best with distinct local variations.
Crottle provides the golden brown which can be likened to the colour of Autumn bracken or a Highland cow. Although some sources recommend soaking this lichen in ammonia or using an alum mordant I have achieved good fast colours by simply simmering the wool with the lichen. Raw fleece does tend to get peppered with flecks of lichen which can be shaken off when the fleece is dry. Any persistent small black flecks will fly off when the fleece is spun.
In Flora Celtica there is a description of layering the lichen with wool in a large boiler set in concrete by a stream and lighting a fire underneath it. The dye bath was topped with a layer of docken (dock leaves) to strengthen the dye. Other properties described include the benefits for feet of wearing crottle dyed socks but also the possible malign effect of wearing crottle cloth at sea for “what comes from the rocks returns to the rocks”.
In 1999 the Flora Celtica project revealed that only one weaver, a woman originally from Hampshire , was still using lichen dyed material. Flora Celtica also mentions the rise of a new generation of natural dyers, fostered by…the Guild of Spinners, Weavers and Dyers. “These enthusiasts are now carrying the dyeing tradition forward in Scotland, experimenting with a mixture of old recipes and new ideas, and occasionally selling their wares. Very few glean anything approaching an income from such activities, but for most devotees that is not the point.” The writing continues to describe the rewards in terms of creativity, interaction with the natural world, freedom of experimentation and “for a few it is something akin to witchcraft”.
Flora Celtica William Milliken & Sam Bridgewater. Birlinn Edinburgh 2004