It might be another tangent but I have spent this evening looking at Topology (doughnut to teacup!). I liked Nick’s suggestion of using two different fragments in one piece with a space in-between. If one was a piece from a plate and the other was from a cup how would you get from one form to another?
Topology is the study of those properties of mathematical objects that remain unaffected by smooth deformations, such as stretching and squeezing, but that don’t involve tearing. If you tried to go from a teacup to a plate the plate would end up with a hole in it because of the hole in a teacups handle, interesting and artistically not necessarily a problem.