Elfbark, more accurately called delventree bark, is a potent stimulant with the unfortunate additional effect of making the user prey to feelings of despondency and fearfulness. For this reason it is often used by slave-owners in Chalced to increase the hours that a slave can work while at the same time dampening his spirit. Taken steadily over a long period it is addictive, some say that even taken sporadically the herb can permanently alter a man's temperament, making him suspicious and defensive even with his closest companions, while eroding his sense of self-worth. Yet even with all these disadvantages, there are times when the risks are worth it for the stamina it may confer in times necessity. It is less volatile a drug than either carris seed or cindin, in those two may lead to wild surges of emotion and false euphoria that may prompt action both foolish and dangerous.

The best quality elfbark is obtained from the new branch tips of very old trees. Incise laterally along the twig and then around it at each end of the cut. Slip a fingernail or knife point under the bark edge and carefully loosen it from the branch. The freed bark will immediately curl into a cylinder. Store it thus in a pouch in a cool dry place until the bark has dried enough to be grated into a powder, which can be infused as a tea.

If the need is immediate, a tea can be made from the freshly harvested bark, but it is far more difficult to judge the strength of the herb's potency from the color of that tea.