Label, pressure-sensitive adhesive label, and printed material

This label (1) is provided with: an optical function layer (13) for transmitting light of a certain wavelength; a light absorbing layer (15) for absorbing light of the wavelength, the light absorbing layer facing the optical function layer (13); and a light scattering layer (12) comprising a hollow body for scattering the light of the wavelength, the light scattering layer (12) being interposed between the optical function layer (13) and the light absorbing layer (15). Upon being heated from an external source, the light scattering layer (12) increases in transmittance with respect to the light of the wavelength.