LOGWOOD
by Cheryl Kolander
Aurora Silk © 2010
The Tree:
The Logwood tree is one of the prettiest trees on the planet. The leaves are like lace. Each little leaflet is the shape of a small heart. Two rows, with their pointy ends attached to a flexible mid-rib, flutter in the breezes. The whole canopy is intersections of these lacy hearts.
The trunk of the Logwood tree grows in a unique formation. It buttresses itself, like most tropical or very old trees do near their roots. The Logwood tree grows this buttress form all the way up the trunk. The older the tree, the more it looks like several trunks that have grown together. Though many trunks may grow from one root cluster, each trunk is individual, even when it looks like six or eight trunks packed tightly. A cross section looks like a flower with many open petals. In really old trees even the buttressing trunks have buttresses!
The sap of the tree is very dark, richly maroon red and abundant. If the tree is wounded it oozes this sap to heal the wound. It looks like dried blood, thus the Latin name Haematozylon = “Bloody sap”.
The Dye Stuff:
It is the heartwood that is the dyestuff. When the tree is cut, the inner wood is a dark rust-red. This is the dyestuff. The outer softwood, or sapwood is a light beige. It contains no dye. The bark is usually thick and rough. Like all barks it contains brown tannins, but it is not the source of the rich purples and black that is the value of this dyestuff.
For quality dyestuff, the tree or a large branch is cut. All the bark and all the sapwood must be removed. This is typically done by hand with a machete. Then the beautiful dark heartwood is rasped, shaved, planed or hammer-milled into a form suitable for dye extraction. The Logwood prepared for Aurora Silk is planed into shavings because I find that this is the most convenient form for maximum extraction. While a finer rasped sawdust will extract more in the first boil, the dust goes right thru a sieve, and fills the textile with annoying bits of wood. I have found this to be so important that I hand carried an electric power planer into the country as part of the Logwood Project.
After shaving or rasping, the wood needs further attention to develop its dye power. As fresh raw heartwood, it is moist and ferment-able. This quality is exactly what makes Logwood such a potent medicine: it is actually a triple anti-oxidant when a tea is prepared from the wood at this stage. For the red medicinal Logwood tea, export quality, the shavings are quickly dried. On the other hand, to develop the finest dye quality, the still moist shavings are placed in a container and allowed to ferment. In the tropics, at 90 degrees even at night, fermentation is complete in a few days. In old books which describe the Logwood trade of the 1800's, the same fermentation could take up to a month in England.
As the red heartwood ferments, the colour changes from red to maroon to deep reddish brown. The best dyewood is in the maroon to deep reddish brown stage. If the wood is over-fermented, the colours given will be greyish and aged looking even when just dyed. They will also turn grey brown, losing the desirable purple cast, much quicker than the rich and vibrant purples of properly aged wood. This is the crux of the problem of dyeing brilliant and fast purples with Logwood extract, a pre-prepared water soluble powder, used for histology staining. Such purples may be bright at first but I have had them turn grey-brown in under a year, with minimal exposure. By comparison I have my own Logwood-shavings dyed silks still vibrant rich purple after 40 years.
To Dye with Logwood
Logwood is a “Mordant Colour”, which means the textile material must be pre-mordanted, that is, prepared by soaking in a solution of some metal that has been dissolved in some acid. Today these are easily obtained as prepared crystals: either Alum (Potassium Aluminum Sulphate; Ammonium Aluminum Sulphate) or Tin (Stannous Chloride), for purples; or Iron (Ferrous Sulphate; rusty iron dissolved in vinegar; iron rich dirt) for greys. Copper (Copper Sulphate) can also be used to give bluer purples.
The dyestuff itself are these maroon mottled wood shavings. Properly prepared, they will have very little contamination of pale sap-wood, dirt or bark. Be aware that someone else may cut down a tree, pushing it all into a chipper-grinder. Then you will see lots of pale pieces, shredded bark and even dirt and rocks at the bottom of the bag. Avoid this, and question the supplier. Remember also that some other dark coloured heartwood, such as ebony which is dark but contains only a little grey dye, could be mixed in. And with an extract pre-prepared, the chance for adulteration is regrettably high. Extract prepared for histology must be US Pharmaceutical certified honestly Logwood, but it's price is extremely high.
Shavings or sawdust, the procedure is the same as for all Natural Dyes: soak the stuff in water till it is well wet, usually overnight for woody dyestuffs. You will get more dye out by this presoak, but if time is an issue, just:
PUT THE LOGWOOD IN SOME WATER AND BOIL.
After 20 minutes of boiling, strain off the dye liquid. Return the wood to the first pot, add more water and
BOIL AGAIN
After two boils almost all the dye is out of the shavings or sawdust. Combine the two waters, and
LOOK AT THE COLOUR.
This is really important: if your water is acid, the liquid will look orange-red. It needs to have added to it: Ammonia (liquid, from the grocery store) until it changes to a nice Concord Grape juice hue. If you are dyeing silk or wool, only use ammonia. If you are dyeing cotton or rayon or hemp, you can also use Chalk (real chalk, Calcium Carbonate), or in a pinch, Baking Soda.
Once the hue of the dyebath is correct, add the textile that has been pre-mordanted. If needed, add more water, so the textile can be moved around, for evenness of dying. Move it about, stir it a bit, and
When it's as dark as you like, it is done. That's all there is to it!
If it's not as dark as you want (and remember it will lighten on rinsing and lighten more on drying), then heat the dyebath. Heat gradually and with stirring, so the colour will be as even as possible. Give it more time: the pot can sit and cool overnight.
Rinse and dry.
Proportions:
Alum 20 – 25% by weight of fibre or
Tin 3 – 5% by weight of fibre (= ½ oz per pound of textile=2 tsp.)
Iron 3-5% by weight of fibre
Copper 3-5% by weight of fibre
Logwood, best, aged from the Dominican Republic Logwood Project:
25% by weight of fibre for dark purple (on Alum), dark violet (on Tin), dark blue-purple (on Copper), dark grey-charcoal (on Iron)
10% by weight of fibre for light purples, medium greys
Proportions and colours obtained with other sources of “Logwood” may vary from this article which is based on 42 years experience with true Logwood : Haematozylon campechianum, and especially with the current finest quality Logwood shavings from the Logwood Project in the Dominican Republic, as developed by Cheryl Kolander, Master Natural Dyer, who is Aurora Silk.
Current world source: www.aurorasilk.com
FAQ:
Acid stains:
Remember how we corrected the too-red, acid dyebath to make it nicely purple? If acid is spilled on the Logwood dyed purple it will turn that part back to reddish. What to do?! Apply as soon as possible the antidote: ammonia, chalk or baking soda, and the purple should re-appear. A neat magic trick could be made up using this colour-shift property!
Black with Logwood – special dye, see directions on True Fibres
FAQ:
Can I grow Logwood?
The natural range of Logwood is the sub-tropics. Any place where it freezes, Logwood would have to be grown in a greenhouse. Since it needs to become a large tree for the dye-filled heartwood to develop, this is not very practical. It is, however a very pretty ornamental, with its small lacey heart shaped leaves.
Originally Logwood grew only in a small area of southern Mexico, the Yucatan and what is now Belize and Honduras, in the Atlantic coastal areas. Its Latin name Heamatozylon campechianum means Blood-red sappy wood from the Bay of Campeche, which is the coast of the Yucatan. The flag of Belize depicts a Logwood tree and beside it two Logwood cutters, one white and one black, with machetes in hand. Belize used to be called British Honduras and was created as a state by the British as a source of Logwood. Until then, from the discovery of this dyestuff in the New World until early 1700's, Logwood harvesting and trade was controlled exclusively by Spain.
In order to increase production of this valuable dyestuff, Spain seeded Logwood in all her territories in the Caribbean. There it has gone wild. It is completely naturalized on Hispanola (The Dominican Republic) and is presumed to be growing on all the islands. The British are credited with bringing it to Jamaica, where harvesting Logwood is a traditional occupation of rural Rastafarians. There are some who believe Logwood arrived on these islands way before Europeans, either brought by the Mayans or by sea-going birds.
Hawaii is a location where Logwood grows happily. There is a specimen tree in the Botanical Gardens in Honolulu whose rapid growth indicates the potential. It has not been planted in Hawaii as a crop for dye but it could be. The Philippines are another likely location where Logwood could be grown. Southern Florida, Texas and California are locations in the continental US that would be worth trying, although an occasional wrapping with blankets during frost warning would be advised.
The easiest way to propagate Logwood is to dig up small seedlings that have sprouted under a mature tree, and transplant them to a desired location. It can also be grown from seed. There is no need to use good farm land to grow Logwood! It prefers poor soil, even growing in nearly pure sand by the beaches. Because the younger branches have some thorns, it is often planted as a living fence. Edging fields, along roads, next to ditches, in gullies, it is excellent for erosion control. Because it is a legume, it fixes its own nitrogen. Because it is deep rooted, it can find water. Because it is producing the natural insecticides that are the dye molecule, it is naturally healthy.
Other Uses
Honey:
Logwood flowers are sweet and abundant. Logwood is an excellent honey tree.
Medicine:
Unaged Red Logwood is considered a tonic tea. It is a triple anti-oxidant. The reddish to blue-toned colour molecule is similar to the anthrocyanins in berries and red wine, that have been proven to have anti-cancer activity. Red Logwood is currently being tested as an anti-cancer treatment. The tea is made cold, by soaking Red Logwood in pure water at room temperature in a closed container, at least overnight. Four cups is drunk as tea over the day. This research is being conducted in the United States and other research is being done in other countries.
Other medicinal uses are given in “A Modern Herbal” by Mrs. M. Grieve, Harcourt Brace & Co 1931, reprinted by Dover 1971 (page 496):
“Medicinal Action and Uses: A mild astringent, especially useful in the weakness of the bowels following cholera infantum. It may by used in chronic diarrhoea and dysentery, in hemorrhages from uterus, lungs, or bowels, is agreeable to take, and suitable whether or not there is fever. It imparts a blood-red colour to urine and stools. It is incompatible with chalk or limewater. The patient should be warned of these two characteristics . . .
“The infusion, internally, combined with a spray or lotion, is said to have cured obstinate cases of foetid polypus in the nose.”
Hair Dye
In the Caribbean Logwood is still used as a natural hair dye. It imparts a glossy blueish black to dark hair. A strong dye solution is made by boiling aged heartwood with Cassia bark – a cinnamon. No mordant is used traditionally, as it is found the natural oils of the hair capture and hold the colour.
Experiments at the Aurora Silk dyeworks have used Logwood with Iron (ferrous sulphate crystals) to first make a black dye. This is worked into the hair, wrapped up and left for a few hours then lightly rinsed. It is best for dark hair on dark skin, or for streaking.
Fencing
Often planted as a living fence, Logwood is also cut and sold for fence posts. Its dye-rich resinous heartwood resists all forms of microbial rot, as well as attack by insects or rodents.
Histology
Logwood is one of the classic stains for microscopic work. Logwood extract can always be purchased from Science suppliers as all the classic texts have pictures of cells stained with Logwood.
PAP smears depend on this staining with Logwood to correctly read the cellular evidence.
Material Safety Data Sheet
This has been prepared for Logwood Extract, Pharmaceutical grade.
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