Development of an etching paste

The recovery of erased identification marks is a problem for the forensic scientist, particularly with respect to vehicles and firearms. The widely accepted procedure for steel imprints is to use Fry's reagent. The present study examined the possibility of forming a paste that may be easier to use. The paste proved to be as effective as liquid in most cases, and often gave better results. The ease of using the paste gives it distinct advantages over liquid reagent.