Abstract: A partially-shielded paperboard tray for heating food in a microwave oven is made from a unitary blank having two sections hingedly joined at a common edge. One section, which forms the bottom stratum of the tray, has a layer of aluminum foil for shielding food along the peripheral wall of the tray from microwave radiation, but the section also has a large aperture to allow the radiation to heat the center of food placed over the aperture. The other section of the blank, which forms the top stratum of the tray, is transparent to microwave radiation and provides an imperforate food-contact surface for retaining food in the tray.