Non-emergency illumination apparatus (10) arranged in use to mark a location of an article, fixture or fitting in an aircraft cabin, the apparatus including: an emitting layer (2) including a photoluminescent material, the photoluminescent material emitting visible light in a first region of the electromagnetic spectrum in response to excitation by light from a second region of the electromagnetic spectrum, different to the first region; and a protective layer (6) overlying the emitting layer, the protective layer transmitting light from the first and second regions of the electromagnetic spectrum, wherein the non-emergency illumination apparatus is constructed and arranged to be placed in proximity to an article, fixture or fitting, such that the apparatus marks the location of the article, fixture or fitting when excited by light from the second region of the electromagnetic spectrum. The illumination apparatus can comprise a carrier matrix. The illumination apparatus aids location of items such as headphone sockets and power sockets in low lighting conditions so calming passengers.