The procedure involves the initial use of an acid etchant followed by the application of an alkali. The alkali, by itself, is an ineffective etchant, but when used after acid, it appears to enhance the contrast between the stamped and unstamped areas. This technique is superior to the practices of putting water on the restoration, the application of petroleum jelly, or the use of an oblique viewing angle to increase contrast. The results of this technique are permanent and easy to photograph. The method has now been used in casework on 11 motorcycle frames. Good restorations were obtained in nine of them. The Victoria Police Forensic Service Department developed a step-by-step method that involves the use of an acid etchant followed by a short exposure to an alkali, with a repetition of this etching cycle as required. The method has now been successfully used on a number of casework frames. Figures, references