The process of making the U.S. dollar is a highly sophisticated and secure operation carried out primarily by the Bureau of Engraving and Printing (BEP). Each stage of production involves advanced techniques to ensure security, durability, and quality. Here’s an in-depth look at the steps involved:
1. Designing and Engraving
- Designing: The dollar’s design is both aesthetic and protective. Artists at the BEP create intricate patterns, detailed portraits, and complex backgrounds to deter counterfeiting. The design incorporates features like microprinting, color-shifting ink, and 3D security ribbons, which are challenging to replicate.
- Engraving: Master engravers then etch the designs onto steel plates by hand or use digital engraving tools. This step requires a high level of skill as they create fine lines and engravings that form the basis for the dollar’s signature detail.
2. Ink and Paper
- The U.S. dollar is printed on a unique blend of 75% cotton and 25% linen, a paper type that’s distinct from regular paper, making it more durable and resistant to wear.
- Inks are specially formulated for durability and color stability, including color-shifting ink for elements like the numeral on the lower right of the $100 bill.
3. Offset Printing
- Process: Offset printing is used to print the background colors on the bills. A specialized offset printing press applies multiple layers of color simultaneously, creating a vibrant and layered background.
- Purpose: This step lays down a base for the subsequent intaglio printing and helps in blending the design elements seamlessly.
4. Intaglio Printing (Plate Printing or Steel Plate Printing)
- Process: Intaglio printing gives the dollar its signature raised feel and unique texture. In this step, ink is applied to engraved plates, and excess ink is wiped off, leaving ink only in the etched lines. The paper is pressed against the inked plates under high pressure, transferring the design and creating raised prints.
- Purpose: This process adds depth and tactile security features, making counterfeiting more challenging.
5. Offline Currency Inspection System (OCIS)
- Purpose: The OCIS checks each sheet of printed currency for defects, such as smudges, misalignments, or ink inconsistencies. This automated system uses high-resolution cameras and scanners to ensure that every bill meets quality standards.
- Inspection Process: The defective sheets are flagged, removed, and replaced to maintain the currency’s quality. Bills that pass the inspection continue to the next stage.
6. Letterpress Printing
- Process: In letterpress printing, serial numbers, seals, and other markings are printed onto the currency. The process uses plates with raised characters for elements like the Treasury Seal and Federal Reserve Seal.
- Importance: This step personalizes each bill, giving it a unique serial number that provides traceability and enhances security.
7. Currency Overprinting Processing Equipment and Packaging (COPE-Pak)
- Process: Currency Overprinting Processing Equipment (COPE-Pak) combines overprinting with packaging. This machinery prints serial numbers and seals and organizes the sheets into large stacks for easier handling.
- Packaging: The currency sheets are carefully packaged for distribution, ensuring that they are securely stored and ready for distribution. Each stack is checked once again for defects, and the stacks are arranged according to bank distribution requirements.
8. Large Examining Printing Equipment (LEPE)
- Purpose: LEPE is used to inspect, cut, and sort the currency sheets, ensuring that each bill meets the stringent quality requirements before it reaches circulation.
- Final Inspection: This step is crucial for catching any final issues or irregularities before the dollars are packaged for distribution. Each stack of printed currency must meet high standards to be deemed ready for circulation.
Through these detailed steps, the U.S. dollar is crafted to withstand wear, prevent counterfeiting, and meet the high demand for the world’s most widely recognized currency. The process showcases a combination of art, precision engineering, and advanced technology, resulting in a secure and high-quality currency.