摘要 |
A color-changing marking composition system, suitable for use in the form of crayons and pencils, comprising a first marking composition comprising wax, a Leuco dye capable of changing color upon contact with a color change-inducing compound, and a solvent capable of solubilizing the dye; and a second marking composition comprising wax and a color change-inducing compound, which is capable of inducing a color change in a Leuco dye with which it is brought in contact.
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