A method of making a vacuum insulated refrigerator structure includes positioning a core of overlapping stacked sheets of fiberglass mat in an envelope of impermeable barrier material. The core is pressed into a predefined three dimensional shape by pressing first and second mold parts together. The core is evacuated, and the envelope is sealed to form a three dimensional core having an airtight envelope around the core. The three dimensional vacuum core is positioned between a wrapper and a liner, and the wrapper and the liner are interconnected to form a vacuum insulated refrigerator structure.