An armature is not always necessary when making smaller clay figures, but some like to use them anyway, because it can do one of two things; it can either make your sculpture heavier or lighter, depending on the materials used.
You will also find that the larger the sculpture, the more necessary it will be to have some type of armature for support. In this way, the armature is rather like your figure’s skeleton. You should always endeavor to give your sculpted figures a good bone structure, or they might not have a leg to stand on, so to speak.
You must also consider the type of clay you are using when choosing materials for your armature. Most anything can be used when working with wet clay (modeling clay, and other clay that doesn’t dry out) and hard air drying clay (clay that you must keep wet until the piece is finished, when it will air dry to a hard form), because these are not normally subjected to heat. In the case of air dry clay, you do have to allow for a certain amount of shrinkage, so this should be taken into account as well.
However, if you are using oven baked clay, or even something that will require firing in a kiln, certain materials, such as plastics and foams, or any other substances that could melt are out of the question. I work a great deal with oven baked clay, so that will be our primary concern in this article, though the same techniques can be used with other types of clay as well.
A great armature for smaller figures, or any figure that needs to be lightweight is aluminum foil, also called “tin foil”. I love using this for many of my figures because it is very shape-able, and can be manipulated to fit any pose.
Should you choose tin foil for your figure’s skeleton, but decide you want your piece to be a bit heavier, you can always begin by wrapping a piece of appropriately sized wood or metal in the tin foil. You would then build upon this with the foil until you have your desired shape. However, if you use any type of metal, be sure that it is not lead based, because obviously lead is toxic, and would be more so when you baked it the oven.
Another good lightweight armature can be made from pipe cleaners. These can be mounted on a wooden base for support, and you can even wrap them in foil for further structure. Toothpicks, dowels, wooden pegs, balls, and even small wood scraps can also be used in a similar manner. These can be assembled by tacking them together with small brads, gluing, using rubber bands, wire ties, pipe cleaners, or sometimes even utilizing foil again.
With smaller figures, even nuts, bolts, and screws themselves can be used as frameworks upon which to build. I have also used such items as broken dishware, pencils, thread spools, and metal lids in the underpinnings of my sculptures. There have even been times that a scrap of wood or a broken dish inspired a sculpture, and then found new life as part of its inner workings. As with all things creative, the only limits are your own imagination.
Source: Over 30 years experience as an artist and art instructor.