A TV crime show I saw recently centered on the ability of forensic scientists to identify a plastic bag as coming from a particular roll: it’s all down to the striations, apparently. This development isn’t fiction, though: researchers at the University of Buffalo have figured out how to identify the individual 3D printer that produced a particular print. The development, called PrinTracker, uses unique differences in the way a printer lays down print material to identify a printer with a claimed 94 percent accuracy.

The researcher behind PrinTracker is [Wenyao Xu], associate professor in the Department of Computer Science and Engineering at the University of Buffalo. He presented the details at a conference in October of 2018 (PDF link) and described how it works. In the study, they printed keys on 14 different printers, then examined each print with a high-powered microscope. In particular, they scanned the print to examine the banding and attachment textures of the print. Banding is the texture on the surface of the model created by the filament being laid down, which is created by the feed rate, temperature, and shape of the outlet of the printing head. The attachment texture is the way that layers are attached to each other. When they examined the sample prints, they found that, after some image analysis and number crunching, they could identify which printer had produced the print with a decent level of statistical accuracy.

It’s an interesting read for those who want to understand how this sort of analysis works. [Xu] speculates that it might be useful for law enforcement in firearms and counterfeiting cases, and the paper also looks at if techniques like scratching or heating a print might obfuscate the identification.

Thanks for the tip, [Sascho]!