AI-rewritten: This is a summary of an article from Tom’s Hardware, rewritten by AI (Qwen, running locally) to make it easier to read. The facts come from the original article – read it for the full story.

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California Governor Gavin Newsom has signed a bill requiring 3D printer manufacturers to include firearm-blocking technology once an industry standard is published by ASTM International. This legislation makes California the second state to enact such restrictions, following New York. Two other states, Colorado and Washington, also have similar bills moving through their legislatures. The law only applies to printers that have not yet been sold, meaning existing devices do not need immediate retrofitting. It regulates the sale and transfer of printers rather than their ownership or use.

The requirement for manufacturers to install blocking features will only begin once ASTM International publishes or adopts a specific standard. The California Department of Justice (DOJ) must check for this standard quarterly starting no later than July 1, 2027, and continuing until July 1, 2029. If the organization has not published a standard by that final date, the DOJ is no longer required to check, potentially halting the creation of specific guidelines for manufacturers.

Currently, two methods exist to detect firearm print files: matching them against a known database or analyzing designs with trained models. Both have significant flaws. Database matching can be easily defeated by modifying file sizes or splitting files, while model analysis often produces false positives, blocking legitimate parts like barrels or brackets that resemble firearms but serve different purposes. The Electronic Frontier Foundation stated in June 2026 that "there is no world where the mandated technology actually works as intended." To address these concerns, the law mandates that the DOJ base its implementation on ASTM International standards rather than defining them itself.