Abstract: A kit comprising a) an aqueous writing ink composition, containing—metal nanoparticles as coloring agent wherein the metal nanoparticles essentially consists of metal and the metal is chosen from silver, gold, aluminum and/or copper and—a dispersing agent, and b) an eradicator fluid containing at least one oxidizing agent. An aqueous eradicator fluid for erasing an aqueous writing ink composition containing metal nanoparticles as the coloring agent, in which the fluid contains an oxidizing agent and—a volatile solvent. A writing instrument containing the eradicator fluid, the use of the eradicator fluid and/or of the kit containing it and a method of correcting errors of a written mark made on a porous substrate.

Abstract: The present invention concerns a kit comprising a) an aqueous writing ink composition, containing—metal nanoparticles as coloring agent wherein said metal nanoparticles essentially consists of metal and said metal is chosen from silver, gold, aluminum and/or copper and—a dispersing agent, and b) an eradicator fluid containing at least one oxidizing agent. It also concerns an aqueous eradicator fluid for erasing an aqueous writing ink composition containing metal nanoparticles as the coloring agent, in which said metal nanoparticles said fluid containing—an oxidizing agent and—a volatile solvent. It further concerns a writing instrument containing the eradicator fluid, the use of the eradicator fluid and/or of the kit containing it and a method of correcting errors of a written mark made on porous substrate.