Potential for carrying dyes derived from spalting fungi in natural oils

Wood colored internally by fungi has long been used by woodcrafters and artisans as a substitute for synthetic dyes. Recent advances in the field of spalted wood have led to methods by which the fungal dyes can be extracted from either a fungal solution or colonized wood and then reapplied to clear wood. This takes the “guess work” out of spalting, as well as the time necessary for fungal colonization; however, it requires organic solvents like dichloromethane, which are toxic and not readily available to consumers. Herein, the authors show that the dyes can be successfully carried and blended together (to increase the range of colors) in a range of natural oils. The blue–green dye of Chlorociboria species, called xylindein, carried best in raw linseed oil, the red dye of Scytalidium cuboideum performed best in Danish oil, although more dye could be carried in raw linseed oil, and the yellow dye of Scytalidium ganodermophthorum performed best in walnut oil. The ability to carry and mix these dyes in easily purchased, nontoxic oils opens up their use to woodworkers who seek to follow the traditions of spalted wood, but do not have the skills or time to work with live fungal cultures or fungal dyes suspended in toxic organic solvents.