Printing systems that are capable of displaying information are becoming increasing important as greater volumes of information become available in digital format. But considering that most documents are only printed for temporary use then discarded, a rewritable printing system would be useful and advantageous for the environment. We have now succeeded in developing a practical rewritable printing system that is capable of rewriting the same sheets more than 500 times. By thermally controlling the coloring reaction of leuco dyes, the system creates stable, highcontrast color images that can be quickly erased so the sheets can be reused and overwritten with new images. This is made possible by our ability to control molecular aggregation structures formed by long-chain molecules in leuco dye developer, which opened the way to our development of functional reversible media based on the supramolecular structure of leuco dye and the long-chain developer.