8-10 strands of round cane available in 3mm or 4mm diameter.
In millinery, 3mm cane is used mainly as an aid in blocking. Where you may use a cord or fabric to push done concave areas in a block, 3mm cane has the added advantage of being rigid and thus pushing down on materials even between pins. It is easily cut and pinned through or you can criss-cross pins over it.
Cane can also be used as a trimming or structure on headpieces if covered or coloured to suit your design. 4mm cane is probably more suitable for this.