Artist Hans-Jürgen Kuhl developed his own manufacturing process to print convincing counterfeit $100 bills. He was delighted with the final product; he felt like he’d won the Monaco Grand Prix in a Volkswagen Golf. Here’s how:
1. Select and Tint the Paper Kuhl found a supplier in Prague who sold him cotton-based paper with a sheet thickness close to that used by the US Bureau of Engraving and Printing. He spent hours mixing inks in half-liter plastic cans, finally coming up with a formula to tint the paper: roughly 83 percent white, 15 percent yellow, 1 percent green, and less than 1 percent black—”for that tiny hint of gray,” he says.
2. Mimic Security Features Kuhl used silk screen to apply features that, on a real bill, are visible only when the note is held up to the light. He created a convincing watermark to the right of the Ben Franklin portrait and added “USA 100” in minuscule print along a vertical security strip. Under and atop the bill’s background color, he printed specks of red and blue to mimic the visible fibers woven into a real note.
3. Deploy Photoshop He used photo-manipulation software to clean up a hi-res scan of a $100 bill, removing certain details like the serial number and the forest-green Treasury seal on the front of the note. He made another image of only the black components on the front of the bill and yet another of the artwork on the back. He also prepared sheets consisting of only bogus serial numbers—about 500 of them in total.
4. Create Digital Files for Each Printing Layer Kuhl duplicated each file image 12 times and laid them out in a three-by-four grid for printing, giving him a sheet of 12 partially completed notes. He did the same for each of the four layers. With these files he was now ready to commence the offset printing process, which involves applying successive layers of color and imagery.
5. Make the Plates From his computer, Kuhl printed the grids onto film—basically transparent paper. Then, one sheet at a time, he placed that film atop specially treated lithographic plates made of aluminum. In a darkroom, he fired ultraviolet light at each plate. Light passes through the film where it’s clear but not where there’s ink. The result after processing, much like with photographic film, is a reverse of the desired image.
6. Print the Bills Kuhl could now clip the plates into his Heidelberg GTO 52 offset printer and run his paper through the machine. The plates are mounted on spinning cylinders and, as they spin, are coated with the appropriate color ink. The image is then transferred from the plate onto the paper, laying down each layer in succession and creating sheets of almost-complete $100s.
7. Fake the UV Security Strip Authentic Benjamins feature a vertical strip of material that shines red when exposed to ultraviolet light. Kuhl made an additional offset plate to print this element. He used it to apply not a color but an invisible UV-sensitive ink that would appear dull red when viewed under a UV lamp. “I printed what I couldn’t see,” he says, recalling the trial and error required to determine just the right amount of ink to apply.
8. Simulate the Texture of Real Cash Certain areas of US currency have a raised texture. To print the scratchy color-shifting “100,” Kuhl mixed green glitter with color-shifting pigment and applied it using a silk-screen press. To prevent this second coating of ink from slumping and blurring, he also applied a UV-sensitive clear lacquer, which dries instantly when exposed to ultraviolet light. (source)