Eucalyptus dyes and wool (or silk) are a match made in heaven... 

 

  

  

 

The eucalypts are an evergreen hardwood genus endemic to the Australasian region embracing approximately nine hundred species and sub-species. Eucalypts are represented across the Australian continent in all but the harshest of the arid interior regions, although they can be found in desert areas marking the positions of soaks and watercourses. Their range extends to 9º N (Philippines) and as far south as 44º in Tasmania [1] with the greatest variety of species concentrated in the temperate zones[2]. Eucalypts have successfully colonised many other parts of the world including southern Europe, Asia and west coast U.S.A.

 

Dyes from the genus are substantive on protein fibres (eg wool, silk), meaning that colour can be fixed without the use of additive chemical mordants. Dramatic colour shifts can be induced by pre-mordanting with other plant material, the addition of scrap metals to the dye bath or the use of dye vessel as mordant. The genus shares an interesting feature with a number of other dye plant families (ie Isatis, Indigofera and Polygonum) in that the potential dye colours are not immediately apparent upon visual inspection of the plant. Eucalyptus cinerea, for example, bears blue grey leaves. Upon immersion in hot water these almost immediately become emerald in colour, after ten minutes simmering they turn khaki and begin to release visible colour into the solution.

 

It should be noted however, that the colour of the dye bath prepared from fresh leaves (gold brown) does not necessarily indicate the colour of the dyed textile, which ranges from green (5min) through gold and orange (about 25 min) and eventually deep chestnut red (45 min)[3]. Leaves from eucalypts will give different colours depending on whether they are used fresh (ie picked green), used dried (picked and dried) or collected from the ground beneath the tree (here again there will be different results depending on the residual colour in the leaf). Leaves picked from different sides of the same tree often give different results.

 

Material processed from species grown in different geographic locations may also offer dramatically different dye results. Additional variables may be created through the choice of dye processes. The traditional approach is to extract the dye by boiling the leaves in water, straining off the liquor, and then heating the textile in the solution. The most intense and clear colours are obtained by restricting processing of plant material to one hour prior to dyeing the textile. Longer cooking facilitates the release of kino from the leaves, inhibiting the dye process and shifting colours toward sticky brown. Eucalypt dyes are at their best in a neutral to acid environment, alkaline or salty water will dull colour outcomes. Another option is that of ‘solar dyeing’. The plant material and the textile to be dyed are placed in close contact (with added liquid) in an airtight container, and left in a sunny spot for at least four weeks (and sometimes months). The liquid may be water, a previously used dyebath, urine, vinegar or solutions left over from the domestic kitchen. In the case of solar dyeing, any material from the tree can be experimented with, whether fresh, dessicated, pre-cooked or partially composted. One tree can provide unlimited colour variations depending on the weather, the dye process, the applied mordants, the dye vessels and the quality of the harvested material.