A method and system for indirectly illuminating an open interior space, such as an open office, includes using individual lighting fixture modules, each comprised of at least one, and preferably a pair of side-by-side parallel linear indirect fluorescent lighting fixture elements suspended at fixed grid pattern locations beneath the ceiling of the open interior space. The lamp housing is comprised of a lamp and a first light valve. Use of primary laminates obtained by such a process to form seals for sealing a container, for food or drink stored at low temperatures, is also described. A power amplifier level controller receives the greater of the voltage envelope signal and the current envelope signal, such as by connecting the output of the voltage envelope detector and the current envelope detector at a common point and conducting the high frequency current components to ground via a capacitor.