A coolable thin metal sheet incorporated in an exhaust nozzle for a gas turbine powered aircraft includes a hot surface, a cool surface and a plurality of triangular sloped depressions which project through the cold gas side of the sheet. Each depression includes a gradually sloped essentially triangular surface which extends gradually in the direction of flow, from a deep, flat faced apex to a flush base, with the apex providing a flat surface perpendicular to the sloped surface. A hole, drilled through the apex admits cooling air which forms a film on the hot gas surface. Utilizing a plurality of such depressions provides precise control of the quantity and direction of cooling gas admitted while allowing use of the thinnest material meeting mechanical requirements, providing optimized film cooling while minimizing nozzle weight.