A plaster (100)is described for providing radiation to skin, e.g. for therapeutic reasons. The plaster (100) is adapted for receiving radiation from at least one radiation source positioned so that at least one projection of the radiation sources in a direction perpendicular to an outcoupling surface of the plaster lies within the outcoupling surface, enclosing for example direct lit radiation. The plaster(100) comprises a homogenizer (120) integrated in the plaster (100) for spreading the radiation so as to homogenize the thus received radiation, and, an outcoupling surface (130) for coupling radiation from said plaster to the skin.