Drawing Charcoal Recipe

While looking up information about pigment properties, history, and recipes, (this brought about by Cassandra Tondro's post concerning paint as a potentially limited resource) I came across the following recipe for Vine Charcoal:

Materials:
twigs, woody vines, or dowels-- untreated wood, at least 2 years of growth, at least 1/4 to 3/8 inch in diameter, extra heavy aluminum foil, fireplace, barbecue pit, ceramics kiln, or other means of heating.

Nearly any kind of wood will make charcoal. IMPORTANT: Do not use treated lumber because of toxic fumes emitted during the roasting process. Twigs may be of any diameter, but very thin twigs would be too weak for drawing. Lumber scraps may be ripped to one-fourth inch squares or larger. The wood will shrink as it turns into charcoal. Cut the twigs to the desired length (five to seven inches is good). Cut off forked joints, and peel away all the bark. If the twigs are cut from fresh, living tissue, they should be allowed to dry for a few days before going on to the next step.

Wrap several dry sticks tightly in extra heavy aluminum foil so that no air may infiltrate the package. Air entering the package would reduce the sticks to ash rather than charcoal. If the aluminum comes in contact with open flame a hole could be burnt through the foil, spoiling the charcoal; so you might wrap a second layer of foil tightly around the package for security. (But don't overdo it; each layer of foil reduces the amount of heat reaching the wood.) Experiment first with five or six sticks per bundle. If the bundle contains more sticks, higher heat and longer roasting time will be required to completely carbonize the wood. Soft wood species, such as pine and cedar, will require less roasting time than hardwood species (such as birch, ash, oak, walnut).

Place the package in the coals of a fireplace or a barbecue pit. It may take several hours (or overnight) in the coals for the sticks to carbonize and then cool down. Do not open the package until it has cooled enough to be handled comfortably. You must be willing to experiment beyond the first attempt. Too much heat will melt the foil. Insufficient heat will produce brands; you should get consistently good results after a few experiments. Charcoal can also be made in a ceramics kiln, which should be vented outdoors. If you use a ceramics kiln, experiment cautiously with temperatures above 300 degrees Celsius (572 degrees Fahrenheit). Hotter temperatures cause rapid carbonization and are hard to control.

This charcoal can be used as is for drawing implements, or you could grind it up in a mortar and pestle to make vine black pigment for ink or paint.

I found this recipe on http://www.jcsparks.com/painted/pigment-chem.htmlwho found it in Pigments Through the Ages. I also noticed that the instructions call for a heating source that vents to the outdoors.

Now I know what to do with all the extra grape vines on some cold winter night!