PURPOSE:To provide a phosphor screen for a color picture tube exhibiting excellent color purity and good brightness and contrast, by mixing the phosphor powder with a substance to react on a phot-adhesive substance to suppress its adhesive strength. CONSTITUTION:A phot-adhesive agent is applied to the inside of the picture tube panel to form a photo-sensitive photo-adhesive film after being dried. Then a shadow mask is installed on the panel and the film is exposed to a light beam, whereby the portions of the film corresponding to those to emit blue light are decomposed to produce an adhesive liquid. Then the blue phosphor powder having been mixed with a substance that will react on the photo-adhesive substance to suppress its adhesive strength, such as, for example, 1.0% by weight of powder of sodium tetraborate, is applied to the film. After development, stripes of blue phosphors are formed on said portions. The green and red phosphors are applied in the similar way in succession, and three color phosphor stripes are thus formed. By such method, a phosphor screen exhibiting excellent color purity and contrast can be provided.

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