Re: Armatures in clay
seru - Your art teacher and Gary R52 both have given the best (and really, the only correct) advice. Some of my art school classes were about 40 years ago, and some were about 15 years ago, but all my instructors said the same thing.
If you have a metal armature in the piece, chances are the armature will shatter your clay when you fire it, because the water in the clay is driven out very quickly, and the clay shrinks quite a bit before really firing. The metal canít shrink, so it generally will split the clay. As Gary said, other pieces in the kiln may be damaged also. You might use an armature that would burn out, such as bits of wood and string, but the gases produced by burning could cause similar problems, and also damage the kiln.
People who fire clay pieces generally build them with no armature, and they also build them hollow, and with fairly thin walls, for just the reasons Gary gave. Itís really best to think along those lines - no armature, and with no area where the clay is more than Ĺ inch to 1 inch thick, depending on the piece.
If you are using some kind of community or school kiln, theyíll probably insist that you follow those rules, and Iím sure they will be glad to help you plan your work.