From the Secret Service website:

U.S. Currency
The Counterfeit Detection Act of 1992, Public Law 102-550, in Section 411 of Title 31 of the Code of Federal Regulations, permits color illustrations of U.S. currency provided:

The illustration is of a size less than three-fourths or more than one and one-half, in linear dimension, of each part of the item illustrated

The illustration is one-sided

All negatives, plates, positives, digitized storage medium, graphic files, magnetic medium, optical storage devices, and any other thing used in the making of the illustration that contain an image of the illustration or any part thereof are destroyed and/or deleted or erased after their final use