Surface tension is the convenient mechanism for synthesis of
round graphite shells less than ~5 millimeters wide. The template for
such round shells can be the exterior of a molten metal droplet, as shown in
optical images of a typical synthesis procedure.
Concave melt surfaces also work, as shown by numerous
graphite bubbles produced by splat cooling.
Where large or electrostatically stressed samples begin to tear
away from their supports, the origami graphite shells have areas of
non-spherical curvature, as shown in this micrograph.
