A microwave energy interactive insulating material is provided. The material may include a susceptor film comprising a microwave energy interactive material supported on a first polymeric film layer, a moisture-containing layer superposed with the microwave energy interactive material, and a second polymeric film layer joined to the moisture-containing layer in a predetermined pattern, thereby forming at least one closed cell between the moisture-containing layer and the second polymeric film layer. The closed cell is capable of inflating upon exposure to microwave energy.