<prompt> Di collar or grease collar is seen in -Punctured wound by sharp weaponLacerated woundFirearm entry woundStab wound  <response>: The synopsis of forensic medicine toxicology ; Dr k.s narayan reddy ; 28th edition ;pg.no 131 A di collar is seen in firearm entry wound ,it is seen as narrow ring of skin ,lining the defect is sharply outlined . This results from the removal of substances from the bullet as it passes through the skin ,i.e bullet lubrication ,gun oil from the interior of the barrel ,lead from the surface of bullet ,barrel debris etc . 