the dissolved ink blots on this paper however when ingredient a is mixed with ingredient b the latter is dispersed into material 3 thus ingredient b contributes to release rapidly the ink adhered closely to the surface of a paper when the paper surface is rubbed with such an eraser containing the material 3 after vulcanization ingredient a does not exhibit essentially perfect miscibility with respect to ingredient b but when ingredient c being a solvent common to both the ingredients a and b is added to them they become miscible one another this is the same theory with that relating to said material 2 wherein the ingredient a is allowed to be miscible with the ingredient b with the aid of the ingredient c as described above when such immiscible ingredients a and b are forcibly mixed together a fragile product is produced accordingly when the surface of a paper is rubbed with such product residuary substances produce so that the product serves as an eraser as mentioned above as a result of containing a large amount of factice plasticizer mineral oil and the like conventional erasers produce residuary substances in the eraser according to the present invention however even if a small amount of a factice a plasticizer a mineral oil and the like are.