An armature is just structure — something the outer material wraps around or leans on. It needs to hold a pose, resist gravity at whatever scale you're working at, and stay stable long enough for the surface material to cure, set or dry. Those requirements sound modest. The problems start when you try to meet them cheaply.
The classic professional option — aluminium wire, the kind sold specifically for sculpture — costs more than most people expect. It's soft enough to bend repeatedly without snapping immediately, stiff enough to hold a shape against light clay or paper-pulp, and it doesn't corrode in any way that bleeds through your surface. If you can budget for it, buy it. But the question of substitutes is worth answering honestly, because people will substitute regardless.
What substitutes actually do
Household aluminium wire — the kind from hardware stores, sold for garden use or electrical work — is coarser and stiffer than sculpture wire, which sounds like an advantage until you try to bend it into a finger joint. You can use it for the main trunk of a structure: a spine, a standing axis. For anything that needs to curve delicately or change direction in tight radius, it will crack the surrounding material rather than flex with it.
Florist's wire — the thin, green-lacquered kind — works surprisingly well at very small scale. It bends easily, holds a gentle curve, and for a figure smaller than five centimetres, the gauge is not embarrassing. The lacquer is a problem if you're covering with anything water-based and expecting adhesion; scoring it lightly before applying paste or pulp helps. The real failure mode is fatigue: this wire is not designed to be repositioned. Bend it twice and it holds; bend it ten times and it snaps without warning at the point of most repeated stress. Build your form, commit to the position, and don't go back.
Wooden skewers and cocktail sticks have an obvious appeal — cheap, available, genuinely rigid. They work well for forms that aren't going to flex at all: a torso you're building up solid, a simple geometric volume. They do not bend, which is a structural feature until it isn't. Any joint between two skewers is only as strong as how you've bonded it, and wood swells with moisture, which means anything you're building up with wet paper-pulp or paste will shift as the armature absorbs water and dries. Not dramatically, but enough to crack a surface that has partially set.
Aluminium foil — crumpled, compressed, taped — is not technically an armature but it functions as bulk. For small sculpture where you just need mass without weight, compact foil into the approximate volume you want and work over it. It doesn't warp, doesn't absorb moisture, and is honest about what it is: a disposable core. No one needs to know it's there.
The actual cost of cheap
The honest reckoning is time, not money. A substitute armature that fails — a skewer joint that shifts, a wire that snaps through a half-dried surface — costs you the surface work on top of it. You're not losing wire; you're losing the hours you spent building up. The calculation shifts if you're working at genuinely small scale, where the loads are light and even a flimsy armature may be adequate for the finished static piece. Scale down the ambition and the budget substitute becomes genuinely viable. Push the scale up or introduce any dynamic tension into the form, and you'll pay for the shortcut somewhere in the middle of a second attempt.
Buy the right wire when you can. When you can't, know what you're trading.