26 U.S.C. § 7303

There may be seized and forfeited to the United States the following: (1) Counterfeit stamps Every stamp involved in the offense described in section 7208 (relating to counterfeit, reused, cancelled, etc., stamps), and the vellum, parchment, document, paper, package, or article upon which such stamp was placed or impressed in connection with such offense. (2) False stamping of packages Any container involved in the offense described in section 7271 (relating to disposal of stamped packages), and of the contents of such container. (3) Fraudulent bonds, permits, and entries All property to which any false or fraudulent instrument involved in the offense described in section 7207 relates.