A method of reusing a notebook comprising: providing: a notebook having at least one synthetic-paper page , wherein the synthetic-paper page comprises a base layer and an ink receptive layer which is waterproof; a thermochromic ink pen which, when used to write on the synthetic-paper page, leaves thermochromic ink markings ; wherein the thermochromic ink pen comprises a thermochromic ink comprising: microcapsules including a leuco dye that can change between colored and colorless forms, and water as a solvent; and wherein the size of the microcapsules is larger than the pore size of the synthetic paper; and a moisture carrier configured to have water diffused therein, the moisture carrier further configured to erase the thermochromic ink markings from the synthetic-paper page by contacting the thermochromic ink markings when it is moist; writing with thermochromic ink on at least a portion of the at least one synthetic-paper page ; and wiping the portion of the at least one synthetic-paper page having the thermochromic ink with the moist moisture carrier in which water is diffused such that the thermochromic ink is erased from the at least one synthetic-paper page . providing: a notebook having at least one synthetic-paper page , wherein the synthetic-paper page comprises a base layer and an ink receptive layer which is waterproof; a thermochromic ink pen which, when used to write on the synthetic-paper page, leaves thermochromic ink markings ; wherein the thermochromic ink pen comprises a thermochromic ink comprising: microcapsules including a leuco dye that can change between colored and colorless forms, and water as a solvent; and wherein the size of the microcapsules is larger than the pore size of the synthetic paper; and a moisture carrier configured to have water diffused therein, the moisture carrier further configured to erase the thermochromic ink markings from the synthetic-paper page by contacting the thermochromic ink markings when it is moist; a notebook having at least one synthetic-paper page , wherein the synthetic-paper page comprises a base layer and an ink receptive layer which is waterproof; a thermochromic ink pen which, when used to write on the synthetic-paper page, leaves thermochromic ink markings ; wherein the thermochromic ink pen comprises a thermochromic ink comprising: microcapsules including a leuco dye that can change between colored and colorless forms, and water as a solvent; and microcapsules including a leuco dye that can change between colored and colorless forms, and water as a solvent; and wherein the size of the microcapsules is larger than the pore size of the synthetic paper; and a moisture carrier configured to have water diffused therein, the moisture carrier further configured to erase the thermochromic ink markings from the synthetic-paper page by contacting the thermochromic ink markings when it is moist; writing with thermochromic ink on at least a portion of the at least one synthetic-paper page ; and wiping the portion of the at least one synthetic-paper page having the thermochromic ink with the moist moisture carrier in which water is diffused such that the thermochromic ink is erased from the at least one synthetic-paper page . <EOS>