[en] Complete text of publication follows. Transparent Cellophane films that are tinted uniformly with dissolved anionic disazo 'Direct' dyes, particularly those whose bisdiazotized benzidine core has been coupled symmetrically at each end by 2-amino-8-naphthol substituted isomerically with sulphonic acid and hydroxyl groups at either para, meta, or ortho locations, are typically lightfast but are readily bleached irreversibly by relatively large absorbed doses of ionizing radiation (10 to 300 kGy). The absence of substituents at the meta or ortho positions of the two adjacent phenyl groups next to the amino-azo bridges contributes to their coplanarity and to stable bonding and radiation resistance through shared hydroxyl groups with the cellulosic substrate. The films are in deep, bright colors (orange, red, violet and blue), each due to a non-overlapping absorption band in the visible spectrum, with a full width at half maximum of approximately 10 nm in wavelength. The films have a thickness of 25.6 μm (± 0.1 μm) and are available in rolls of either 30 m by 0.51 m or 60 m by 0.76 m. The radiolytic bleaching process occurs mainly through reductive attack of the dye molecule by the transient solvated electron, with breakage of the azo double bonds and subsequent rearrangements to colorless bridged substituents, at initial reaction rate constants in the range 10⁵ to 10⁶ s^-1. For dosimetry using spectrophotometry, the radiation response of such dyed films is independent of absorbed dose rate but is markedly dependent on temperature and relative humidity during irradiation. The latter behavior is largely due to oxidative competition by hydroxyl radicals owing to the hydrophilic nature of Cellophane