Microcellular foam sheet and processes of making and using

A solid state foamed microcellular foam sheet for use in forming a container, the microcellular foam sheet comprising:

• a central foamed section defining a foam layer within the microcellular foam sheet and having a first population of cells within which are interspersed a second population of cells having a smaller cell size than the first population of cells, wherein the second population of cells are formed in the material defining the first population of cells within the central foamed section;
• and
• one or more discrete unfoamed sections defining a skin layer on one or both sides of the central foamed section.