A multiple-layer optical film comprises: a Supporting layer; a printable intermediate thin layer formed on the Supporting layer; and an upper structured-surface or upper prismatic layer formed on the printable intermediate layer. The inter mediate thin layer is imprinted with a plurality of notches recessed in the intermediate thin layer to be respectively engaged with a plurality of lower protrusions protruding downwardly from the upper layer for firmly interlocking the upper layer with the intermediate layer which is formed on the Supporting layer.