You didn't mention how large you wanted your
sculptures to be--is this a group effort (large
single) or individual sculptures?
I don't think anyone has mentioned using plaster gauze
for sculpture. This material gives a product that is
strong and relatively lightweight, yet paints up
nicely. My suggestion would be to construct an
armature from aluminum wire for small sculptures, wood
scraps and wire for larger. You can "bulk up" wire
armatures with aluminum foil or paper towels wrapped
around the wire before coating in plaster gauze.
Gauze comes in rolls or sheets. You simply cut the
gauze with scissors into manageable pieces, then dip
the piece in water then drape the gauze onto the
armature. Smooth out the plaster to cover the gauze
texture and wait around 15 minutes to harden the
plaster. Because of the quick set up features of
plaster, you can build multiple layers on a sculpture
in a relatively quick time, which makes the work
extremely strong. Finish the work in acrylic paint
for a long lasting finish. Wire armatures can be made
into virtually any shape, realistic or abstract, and
the gauze simply follows the shape, whatever it is.