Starna has developed the second-generation of their polymer references based upon new proprietary dyes. With increased stability and resistance to photo-bleaching, the performance of these materials is extended to allow their use as relative photometric intensity references. Their development has been under Starna’s ISO 17034 accreditation, which has ensured appropriate stability and homogeneity studies. These materials can, therefore, be used to qualify a wide variety of fluorescent instrumentation and provide traceability of measurement, facilitating comparison between measurements on a given instrument and between systems. They are available in a variety of physical formats and concentrations, which may be optimised for specific instruments and applications. A range of concentrations further provide the possibility for linearity verification. Starna offer a range of polymer, glass and sintered formats as well as sealed liquid fluorescent reference materials to allow the testing of wavelength, spectral response, sensitivity and signal-to-noise ratio.