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greement n" 228 0 ‘emission’. Ultraviolet-induced luminescence (UVL) images record the emission of light (luminescence) in the visible region (400-700 nm) from a subject when this is illuminated with UV radiation. This image is used to investigate the distribution of luminescent materials, such as organic binders and colorants.”®? Some inorganic materials also show luminescence properties, such as, for example, some inorganic pigments including zinc oxide with impurities.*°*” The absence of luminescence does not imply the absence of organic materials. Visible-induced infrared luminescence (VIL) images record the emission of radiation (luminescence) in the infrared region (700-1100 nm) from a subject when this is illuminated with visible light. This image characterizes the spatial distribution of pigments such as Egyptian blue, Han blue, Han purple" and cadmium-containing pigments.’? This technique is very sensitive and can reveal even single particles of such pigments. Visible-induced visible luminescence (VIVL) images record the emission of light in the visible region (500-700 nm) from a subject when this is illuminated with visible light (400-500 nm). This image is useful in the characterisation of the spatial distribution of red and yellow lakes. Version No. 1.0 Date : 14/10/2013
