A packaging product taking the form of a thermally insulating packaging material includes a first multi-layer film bonded to a second layer of multi-layer film. Each multi-layer film can include one or more polymer layers and one or more metallized layers. The multi-layer films are bonded to each other with a pattern that leaves a number of inflatable cells dispersed across a surface of the sheet. At least one end of the sheet can be left unbonded. The uninflated packaging product can be stored and distributed in its uninflated state prior to it being used as a packaging material. Once ready for use, the cells can be inflated through the unbonded ends and the unbonded ends of the sheets can then be sealed to form a robust sheet of thermally insulating packaging material.