The reagents needed to appear metal stamping handwriting are encapsulated in the ampere bottle, and then the ampere bottle is divided into two groups of a liquid and ethyl liquid, which are encapsulated with plastic tubes. When used only need to smash the ampere bottle to make the reagent mix, cut the seal of the plastic tube so that the solution flows out, A, B two solutions alternately noted on the potential metal handwriting, after a period of time can be shown. Because each reagent is stored separately in an ampere bottle, long-term preservation does not fail.