Paper and board -- Determination of CIE whiteness, C/2 degrees (indoor illumination conditions)
ISO 11476:2010 specifies the procedure to be used for determining the CIE whiteness of papers and boards, in order to obtain values which correspond to the visual appearance of white papers and boards, with or without fluorescent whitening agents, when they are viewed indoors. It is based on radiance factor data obtained over the full visible spectral range (VIS) in contrast to the measurement of ISO brightness, which is limited to the blue region of VIS. ISO 11476:2010 also specifies the procedures for the determination of CIE tint values and the fluorescent component of CIE whiteness.
In addition, it specifies a method for adjustment of the UV content to correspond to that of CIE illuminant C, since the results obtained when fluorescent whitening agents are present are dependent upon the UV content of the radiation falling upon the sample. The CIE illuminant C is taken to be representative of indoor illumination conditions because it contains a suitable proportion of UV radiation. This method is not applicable to coloured papers containing fluorescent dyes. It is specific to the situation where the fluorescence occurs in the blue region of the visible spectral range.
ISO 11476:2010 is read in conjunction with ISO 2469.