California Sues Polymaker for Allegedly Promoting 3D-Printed Ghost Guns

Lawsuit Filed Against Polymaker

The State of California, through San Diego County Counsel, filed a civil lawsuit against Polymaker LLC on October 5, 2026. Polymaker, a major 3D printing filament manufacturer with headquarters in Shanghai and U.S. operations in Houston, is accused of marketing its filament to appeal to gun enthusiasts. This marketing strategy, according to the complaint, transforms otherwise harmless PLA filament into a regulated "firearm precursor part" under California law.

Definition of Firearm Precursor Part

California law defines a firearm precursor part as "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 lawsuit acknowledges that 3D printing filament itself is not illegal, but argues that Polymaker's marketing practices fall under this definition. The County is seeking disgorgement of profits, civil penalties, and injunctive relief.

Role of Sean Aranda

A central element of the prosecution's case involves Sean Aranda, known as The 3D Print General. Aranda, a 3D printing expert and gun enthusiast, was banned from YouTube in 2023 for firearm policy violations. Polymaker, which had previously sponsored his channel, subsequently hired him as Head of Customer Experience and later as Senior Technical Account Manager. The complaint mentions Aranda 65 times, implying he was hired specifically for his connections to the 3D printing gun community to foster Polymaker's online community.

Marketing Tactics Under Scrutiny

The prosecution also scrutinizes the use of affiliate links, a common marketing tactic among online content creators. While affiliate links are widely used to promote various products, the lawsuit attempts to connect Polymaker's use of this tactic, particularly through figures like Aranda, to the illegal proliferation of ghost guns. The complaint suggests that Polymaker actively cultivated and monetized the "ghost gun" community through these methods.