Have you created a doll body from polymer clay and then have it collapse while baking in the oven, have small parts break after baking, or use so much clay that it is too thick for baking? For these reasons you must use a better internal structure to support the clay and to reduce bulk.
Think of the internal structure as the strong, sturdy skeleton for your doll. The wires for an armature can be aluminum, brass, stainless or galvanized steel. Small scale doll armatures can be made from 14, 18, 20 and 22 gauge wire. Some use gold wire to strengthen tiny fingers. Small brass rods and tubes can also be incorporated. The armature wire can be extended beyond the limb it supports to provide a way to mount your doll to a base, or to secure it to an accompanying figure or object.
You can add aluminum foil or sculpting epoxy, such as Magic Sculpt, to your wire armatures. They are used to reduce the amount of clay needed to complete a doll body and has the added advantages of reducing curing time and making the doll body stronger. I
Some dollmakers say that it helps to apply polyvinyl glue, such as Sobo glue, to your wire armatures before applying clay over the wire to provide a strong bond between metal and clay. Some wrap the metal wire with masking tape and some cover the doll's wire armature in fabric and stuff with batting.