Fig. 2From: Exploring elucidation of red dye mixtures on woolen historical textiles via non-destructive spectroscopic analysis and multivariate cluster analysisConfigurations tested for fiber optic reflectance spectroscopy tested. a Detection probe and external light source angled at the same swatch spot; b bifurcated probe mounted on a metal holder at a 90° angle from the textile without external illumination; and c bifurcated probe mounted on a pistol gripBack to article page