3. One Part Mold

A simple object is defined by the lack of undercut. When there is no undercut the object can removed from it's largest side e.g. the bottom. This large size will be mounted to a mold form, the part that defines the outside of the mold.  

Minor refinements will help mold release: 2 degree draft angle, and chamfered edges.Note the bottom is not chamfered because this would cause undercut and lock the part in place, or make it difficult to remove from the mold.