Nature's Scarlet from an African Heartwood: Dyeing with Camwood

Camwood, a shrubby African tree. The colour; carnelian, scarlet perhaps, or vermillion. The freshly cut heartwood is pale brown, the hard, close-grain of the tree rapidly darkens to an intense red or hearty orange colour as it oxidises upon exposure to the ambient air. Known as Bois Rouge in French. The French version sounds like a decadent food that you could smear all over your face, but then most French words sound like that.

Camwood powder

If you were to encounter the tree between February to May, you would find it in fragrant blossom, with small white petals surrounding yellow centres. In October, pods containing one or two shiny seeds hang amongst the glossy leaves. It’s slightly weeping boughs lend the camwood tree an ornamental grace, and the tree often cultivated for use in towns; it's habit for fast-growth and compact foliage useful for shade and hedging. The plant’s wood, foliage and seeds are utilised in various cultures for diverse applications.

Sustainability of Camwood Trees

Camwood or Baphia Nitida is native to West and Central Africa and successfully introduced to India, Singapore and Sri Lanka. It comprises 45 species, found mostly in West African tropical rain forests, and is at home in the wild or thriving in an urban landscape.

The Camwood tree grows sustainably, it is fast to mature, and thus not at risk regarding its survival (yet, and hopefully forever). It is reassuringly classified as 'Least Concern' in the IUCN (International Union for Conservation of Nature) Red List of Threatened Species (2011) but noted as requiring constant monitoring due to its widespread use. That’s a yay from us.

 Camwood blooms. Image by  Alexey Yakovlev . "Baphia nitida (Fabaceae)" shared under a Creative Commons (BY-SA) license.

Camwood blooms. Image by Alexey Yakovlev. "Baphia nitida (Fabaceae)" shared under a Creative Commons (BY-SA) license.

Endless Hues and Applications

A valuable hardwood, Camwood is used for building materials, making dye, the base of many folk medicines and within cosmetics. Amongst African tribes, various parts of the plant are treated in different ways and utilised as applications for a myriad of ailments including rheumatic pain, gastrointestinal disorders and as a topical treatment.

Suited to woodworking, Camwood can be planed and carved successfully, making it useful for posts, tool handles and rafters, as well as in decorative crafts and furniture making.  It’s versatility and durability allowed Camwood to be widely exported to Europe from the 17th century, and then to North America from the 18th century.  European and American dyers valued the ‘redwood’ dye for its supreme colouring power for textiles such as wool, cotton and silk.

Camwood colour on brush

This remarkable botanical has many other benefits: In the south-east region of Nigeria, the Igbo people, who make up one of the largest ethnic groups in Africa, incorporate the highly nutritious seeds into their food. It is also imbibed as a remedy for many ailments, with its roots firmly in traditional practices indigenous to various ethnic groups, including the Binis, a cultural group from the region of Benin, Nigeria, and the Ehotile people of Côte d’Ivoire.

Camwood has also been used cosmetically for many years, and, among other benefits, is today renowned for its antioxidant properties and soothing effect on sunburn. In traditional medicine, an ointment is often made from the leaves and applied as an anti-inflammatory. The powder can be mixed with sweet almond or coconut oil to make a paste which is then spread upon the skin and massaged gently for a cleansing and moisturising effect. Add to African black soap for a nourishing facial scrub.

Fifty Shades of Crimson

Just like a Sanguine disposition, Camwood charms pants off and loves to try its hand at everything. It’s versatility as a botanical is impressive, however, as a dye Camwood can be stubborn, but worth the coaxing. Camwood is classified as an ‘insoluble redwood’ along with Red Sandalwood (Pterocarpus santalinus) and Padauk (Pterocarpus indicus). The latter two both sometimes used as a substitute with similar dyeing properties to Camwood.  However, Camwood can exhibit a somewhat bluer tone and is, at times, regarded as easier to work with, with its dye more readily soluble in water.

In it’s native Benin, ceremonial masks are painted with a dark red brew, extracted by mashing and boiling the roots; while in Nigeria, beehives made from hollowed, cured gourds are painted with swarm-attracting deep red Camwood colour.  The Yoruba honey hunters of Southwestern and North Central Nigeria apply the dye in the form of a paste, to deter bees from stinging.

In sub-Saharan West Africa, a powder made from the duramen (heartwood) is used to make a body paint, which is believed to contain magical powers for the wearer.  The Krou and Guéré of the Côte d'Ivoire have historically used Camwood as part of their ceremonial traditions, and it is the dye used on powerfully ferocious-looking masks which feature bulging eyes, open mouths and horns.

The Dyeing Procedure

Dyeing hessian using Camwood alkaline dye solution

Amongst some other secondary components, the principle dyeing compounds within camwood are santalins and santarubins. To extract the colour from the wood shavings, they are soaked in alcohol for several weeks, strained, and then added, with water, to the fibres which are to be dyed. The dyebath is heated gently, and the textile left until they have absorbed the colour.

Camwood dye solution and powder

A range of factors affects the final result of the dyed fibre, these include:

*  Extraction time;

*  The temperature of the extraction bath (in general the hotter, the stronger the extraction, but then, degradation can occur at higher temperatures);

*  pH of the extraction liquid;

*  The concentration of dye in the aqueous solution, and;

*  The quantity of fibre material within the extraction bath.

Hessian strips in Camwood dye solution

The dye compounds within the wood do not dissolve readily in water so it needs to be soaked in around 45% alcohol/water, or closer to neat alcohol the more stubborn the colour is to draw out. The time of soaking can vary from a few hours up to several weeks dependent on the size of the wood pieces and the volume/volume (V/V) % of the solution. For example, if you use the pulverised Camwood powder that has a greater surface area exposed and at 80-100% alcohol solution the soaking time will be lower. It also depends on the strength of the red hue you are aiming for and the material you are dyeing.

Different fibres have differing optimal dyeing pHs. For example, cellulose fibres dye more efficiently at higher pH (more alkaline), whereas silk and wool dye better in more acidic environments (low pH). Paula Burch provides a useful rundown of these considerations.

pH strips to test the acidity or alkalinity of your solution can be purchased from many outlets online such as Lotioncrafter.

A range of alkali materials can be used to increase the pH of the solution, such as sodium carbonate (soda ash), sodium hydroxide (NaOH) and trisodium phosphate and also acidic (lower pH) additives can be used such as citric acid and sodium silicate. The agent used and the concentration of the solution depends on the type of fibre you are dyeing and the extent of colour you are seeking. It’s about experimenting for yourself and seeing what works for you. Also, check how long the dye lasts in the garment over time before it fades, if it fades (colour fastness).

Hessian dyed with Camwood

Mordants and Fixatives

Each type of natural fibre has a different structural makeup and so requires conditions to ensure the dye compounds adhere and will not fade (detach). Natural fibres such as cellulose and silk demand a helping hand for the dye to adequately adhere to the textile. That’s where mordants come in. The most common mordants are metallic ‘salts’ (not an edible kind) including alum (potassium aluminium sulphate), copper (copper sulphate), iron (ferrous sulphate), tin (stannous chloride) and tannin (tannic acid), with alum being the safest to use.  Some mordants also influence the final dye colour which may or may not be desirable. For more detailed coverage of mordants and fixatives check out Sarah’s info over at Wearing Woad or Samantha Jane’s information at All Natural Dyeing. For a comprehensive list with quantities head over to Griffin Dyeworks. We highly recommend checking out Alpenglow Yarn’s candid post on mordants packed full of useful information.

Hessian dyed with Camwood drying

Safety First:

Alcohol is highly flammable!!!! Store covered and not near any heat sources!!

Always add acids and bases to the water, rather than the other way around to avoid violent reactions. Much less applicable with soda ash but it's better to be in the habit.

Always wear gloves, safety glasses and protective clothing when dyeing. Acids and bases can be irritating and corrosive to the skin. Also, wood powders can often irritate mucous membranes so be careful not to breathe in the dust and wear a mask if needed.

Never mix acids and bases together, or you may have nasty corrosiveness in your face. We would rather have pie.

As for the pH adjusting, always wear full protective clothing when dealing with mordants and fixatives, some create noxious gases when dissolved in water, and they can be corrosive.

Some great resources on natural dyes and dyeing techniques:

Books on Dyeing:

Natural Colour by Sasha Duerr

Natural Dyes and Home Dyeing Rita J. Adrosko

Natural Dyes: Sources, Tradition, Technology, and Science by Dominique Cardon

Koekboya Natural Dyes and Textiles A Colour Journey From Turkey to India and Beyond by Harald Bohmer

Dyes and Tannins by P. C. M. Jansen, D. Cardon

Sites on Dyeing:

All Natural Dyeing

Wearing Woad

Griffin DyeWorks

A great online resource courtesy of Ashis Kumar Samanta and Adwaita Konar from the University of Calcutta is available here. The article includes suggested conditions for use of Camwood.