Double-edged knife produces -
With a double-edged weapon, the shape of the wound will be elliptical or slit-like and both angles will be sharp or pointed.
With a single-edged weapon, the shape will be triangular or wedge-shaped and one angle of the wound will be sharp, the other rounded, blunt, or squared-off. Blunt end on the skin may have small splits, so-called "fish-tailing" if the back edge of the blade is heavy.
A spear or another round object causes a circular wound.
Elliptical wound
Linear wound
Circular wound
Curvilinear incision