Specification document for using Reference Materials to establish traceability and evaluate measurement uncertainty for instrument used to measure luminance and reduced luminance coefficients of road surfaces

im of this report is to investigate available materials for 3D printing to be used to design Reference Materials (RM) for the planned Inter- comparison on Luminance coefficient that will be arranged during the project EMPIR 16NRM02. The report presents the analyses carried out to characterize optical properties of the different materials: gloss, spa- tial luminance distribution, fluorescence and spectral reflectance. The report also presents two different solutions for the RM design and the selected set of artefacts that will be used during the intercomparison.