Quantum efficiency of fluorescent dyes in cloth

Based on an additional hypothesis of the Kubelka‐Munk theory, different equations describing the propagation of fluorescent light in cloth are proposed and a much simpler formula relating to the quantum efficiency of fluorescent dyes with spectral radiance factor is obtained. The polyester, wool and cotton samples were dyed with disperse and acid fluorescent dyes in the laboratory. With the spectral radiance factor of fluorescent samples measured via the two‐mode method, the quantum efficiencies are evaluated in terms of the new formula. These show good agreement to quantum efficiencies calculated using an alternative formula.