In a two component system, non-polymer surfaces form when a positive net amount of energy is required to break self-interactions and form non-self-interactions.
The non-self-centering action of the independent jaws makes centering highly controllable (for an experienced user), but at the expense of speed and ease.
Non-microbial exogenous (non-self) antigens can include pollen, egg white, and proteins from transplanted tissues and organs or on the surface of transfused blood cells.
In order for a mesh to appear attractive when rendered, it is desirable that it be non-self-intersecting, meaning that no edge passes through a polygon.