Researchers at the University of Buffalo have discovered that 3D printers have fingerprints, essentially small differences in design that can be used to identify prints. This means that researchers can examine the layers of a 3D printed object and point out exactly which machine produced the parts. “3D printing has many wonderful uses, but it is also a counterfeiter’s dream. Even more worrying, it has the potential to make firearms more readily available to people who are not allowed to own them,” said Wenyao Xu, lead author of the study. The researchers found that small wrinkles can be used on each layer of plastic to identify the type of printer model, the filament, the size of the nozzle and other factors that cause slight imperfections in the patterns. They call their technology PrinTracker.

“Like a fingerprint for a person, these patterns are unique. As a result, they can be traced to the 3D printer,” the researchers wrote. This process works primarily with FDM printers such as the Makerbot, which uses long filament coils to deposit plastic layers on a construction board. Because the printers used in 3D printed guns are generally more complex and more expensive, there could be less variation in individual layers and, more importantly, layers may be more difficult to discern. However, for some simpler plastic parts there may be variations. “3D printers are designed to be the same. But there are slight variations in their hardware created during the manufacturing process that lead to unique, unavoidable and immutable patterns on every object they print” said Xu.