An aircraft emergency sign comprising a base layer comprising a photoluminescent material arranged to be charged by electromagnetic wavelengths in a first range and arranged to emit electromagnetic emissions in a second range; a barrier layer; and a print layer, the print layer being printed with at least one of a color or a pattern wherein the print layer is above the barrier layer and on a side remote from the base layer, and wherein the print layer is at least semi-transparent to wavelengths in the first range and the second range, the sign further comprising a mask layer provided between the barrier layer and the print layer.