Insulated shipping container and method of making

A thermally insulating shipping container, comprising:

• an outer container that is a box formed of paper and having a floor and four sidewalls;
• an inner container that is a box formed of paper and having a floor and four sidewalls, a space interior to the four sidewalls of the inner container defining an inner cavity to hold a product for shipping in the shipping container;
• a recyclable or compostable thermal insulation material formed primarily of plant fiber disposed between the sidewalls of the inner container and the sidewalls of the outer container;
• a barrier formed of paper and positioned to cover at least a portion of a top surface of the thermal insulation material between the sidewalls of the inner container and the sidewalls of the outer container, the barrier comprising
• four horizontal sections positioned substantially co-planar with an upper rim of the four sidewalls of the inner container and below an upper rim of the four sidewalls of the outer container, each respective horizontal section of the four horizontal sections positioned between a respective sidewall of the four sidewalls of the inner container and a respective sidewall of the four sidewalls of the outer container and extending along an entirety of the upper rim of the respective sidewall of the inner container, and
• a plurality of overhanging sections with each overhanging section extending downwardly from an inner edge of a respective horizontal section from the four horizontal sections and along a respective corresponding sidewall from the four sidewalls of the inner container and along a side of the thermal insulation material;
• and
• a rectangular insert of insulative material that fits inside the four sidewalls of the outer container and on the barrier and above the inner cavity.