31 U.S.C. § 5144: Providing impressions of portraits and vignettes

The Secretary of the Treasury may provide impressions from an engraved portrait or vignette in the possession of the Bureau of Engraving and Printing. An impression shall be provided—(1) at the request of—(A) a member of Congress; (B) a head of an agency; (C) an art association; or (D) a library; and (2) for a charge and under conditions the Secretary decides are necessary to protect the public interest.