| 摘要 |
Paper for use in the production of security documents incorporates planchettes which have incorporated therein or applied thereto a substance which is capable of taking part in a color-forming reaction. A second substance which is capable of taking part in a different color-forming reaction may be incorporated in other planchettes. When a reagent or reagents is or are applied to the security document to verify the authenticity of the document the substances change color by the color-forming reactions.
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