Mold and method for manufacture thereof

A mold comprising:

• a first mold portion and a second mold portion reversibly engageable between an open position and a closed position that defines a mold cavity, the first mold portion comprising a first part-line surface and the second mold portion comprising a second part-line surface,
• the first part-line surface comprising a projection portion and the second part-line surface comprising a receptacle having a resilient portion therein, the resilient portion comprising a non-arched surface;
• wherein:
• (i) in the open position of the mold, the receptacle comprises a first area occupied by the resilient portion and a second area unoccupied by the resilient portion adjacent the second part-line surface, (ii) in the closed position of the mold, at least a portion of the second area is occupied by the resilient portion, and (iii) in the closed position of the mold, the resilient portion extends to the surface of the second part-line, but does not enter the mold cavity, wherein the projecting portion has a wedge shape with an apex that is narrower than a width of the non-arched surface of the resilient portion.