Abstract. A method is described for measuring the spectral reflexion of fluorescent pigments for incident monochromatic light covering the ultra-violet and visible regions of the spectrum. The results are recorded in the form of a square table from which quantum efficiencies and spectral reflexion curves for sunlight or any illuminant of known energy distribution are calculated. Data are given for a red pigment and an optical bleach. Three curves only, showing the variation of tristimulus values with incident wavelength, are sufficient for the calculation of colour. The curves of tristimulus values may be derived from the reflexion curves or measured directly by a template colorimeter.

Print publication: Issue 6 (June 1954)
Received 15 September 1953