The envelope was stamped in black ink: "For your eyes only." The two men asked him to sign for it, and when Castellano signed the receipt, he saw that his supervisor had signed it, and strangely enough so had the Undersecretary of the Treasury and the Undersecretary of State also. This envelope had been around. Following proper form, Castellano waited until the two men were out of his office before opening the seal of the envelope. Inside were two small envelopes and a note. The first small envelope was marked: "Open this first." The second warned: "Do not open without specific telephone authorization." The note from his supervisor said: "Jim, tell me what you think."

Castellano opened the first envelope at the corner and shook out a mint-fresh fifty-dollar bill. He held it in his hands. The paper felt real. The most common mistake in counterfeiting was the paper. An experienced bank teller, ruffling through stacks of bills, could spot funny money easily, sometimes even with his eyes closed. There was a feel to counterfeit, a cheap paper kind of feel because the rag content was usually deficient.

This bill felt real. He rubbed the corners of the bill against a piece of plain white paper, very hard. The green ink smeared off. This was a test not so much of the ink but of the paper. The special money paper of the United States government was not porous enough for the proper ink to dry. So far this bill looked good. In the corner of his office, underneath blowups of now-famous counterfeits—like the Hitler fifties that were so good they just let them stay in circulation—was the ultraviolet light. Many counterfeiters, in an effort to get the right feel, which would fool a bank teller, would use commercial high rag content paper.

The flaw was that commercial rag paper was made of used cloth and used cloth had been washed at least once and all detergents left traces that would show up under ultraviolet light. United States money was made with unwashed rags. New rag content.