The Secretary of the Treasury shall engrave and print United States currency and bonds of the United States Government and currency and bonds of United States territories and possessions from intaglio plates on plate printing presses the Secretary selects. However, other security documents and checks may be printed by any process the Secretary selects. Engraving and printing shall be carried out within the Department of the Treasury if the Secretary decides the engraving and printing can be carried out as cheaply, perfectly, and safely as outside the Department.