San Diego County Counsel filed a civil complaint against Polymaker LLC on October 5, 2026, in San Diego County Superior Court, acting on behalf of the People of the State of California. The suit, brought by the county’s newly formed Consumer Fairness and Public Protection Division, argues that Polymaker’s marketing to the 3D-printed gun community turns its PLA filament into a regulated “firearm precursor part” under California law, which covers “any article marketed or sold to the public to become or be used as the frame or receiver of a functional firearm once completed, assembled or converted.” The county wants disgorgement of profits, civil penalties, and an injunction.
The complaint does not claim the filament itself is illegal. Instead it centers on Sean Aranda, known online as The 3D Print General, who Polymaker had sponsored with a khaki-colored PLA Pro creator spool. After YouTube banned Aranda’s 123K-subscriber channel in 2023 over firearm policy violations, Polymaker hired him; he is now Senior Technical Account Manager after a stint as Head of Customer Experience. Aranda appears 65 times in the 39-page filing, with prosecutors arguing he was specifically hired for his ties to the gun-printing audience rather than for general qualifications.
The suit also targets Polymaker’s affiliate program, which asks applicants for name, location, and follower counts but not content type, stating “if you love Polymaker, you qualify.” Polymaker is headquartered in Shanghai with U.S. operations in Houston.
The case tests whether a material supplier can face California civil liability for how third-party creators use its product, even where that use isn’t illegal in the manufacturer’s home state. A win for the county could extend the theory to any raw material, software, or hardware maker whose marketing reaches an audience doing something legally gray elsewhere.