Abstract: A marker apparatus includes a housing, a current controller that is electrically connected to an electrode, a pad connected to the electrode for retaining an electrolytic fluid, and a removable cover. The removable cover retains an insulated stencil to an outer surface of the pad. The insulated stencil defines at least one permeable portion therein and a portion of the outer surface of the pad adjoins the at least one permeable portion. The at least one permeable portion can be formed as at least one opening defined through the insulated stencil, in which the portion of the outer surface of the pad extends into the at least one opening. The current controller provides an electric current from the electrode through the at least one permeable portion that is electrically connected to an object to be marker. The marker apparatus can include an on-board reservoir of electrolytic fluid and an actuator.