Washington house bill 2321 regarding 3d printers

Washington House Bill 2321 is proposed legislation in the U.S. state of Washington that requires all 3D printers sold in the state to include firearm-blocking technology. Prefiled on January 8, 2026, and referred to the House Civil Rights & Judiciary Committee on January 12, the bill would impose Class C felony penalties of up to five years imprisonment and $15,000 in fines for corporations that sell non-compliant printers after July 1, 2027.^[1][2]

The bill is sponsored by Democratic state representatives.^[2] No hearings have been scheduled as of January 21, 2026, and no amendments have been filed.

The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives issued a rule in 2022 clarifying that weapon parts kits and unfinished frames fall under the definition of "firearm" in the Gun Control Act of 1968. This rule required ghost gun kits to carry serial numbers and be sold through licensed dealers with background checks.^[3]

On March 26, 2025, the Supreme Court upheld this rule in Bondi v. VanDerStok by a 7-2 vote. Justice Neil Gorsuch, writing for the majority, affirmed that weapon parts kits and partially complete frames that are "readily convertible" into functional weapons fall under the Gun Control Act's purview. The majority reasoned that just as a disassembled table is still a table, a kit containing all necessary parts to assemble a firearm—such as Polymer80's "Buy Build Shoot" kit—is effectively a firearm.^[4] The ruling was a statutory interpretation challenge under the Administrative Procedure Act; it did not address Second Amendment claims regarding home firearm manufacture.^[5]

The consumer 3D printer market relies on open-source firmware. Marlin firmware, created in 2011, states on its homepage that it "drives most of the world's 3D printers." It is used by manufacturers including Ultimaker, Prusa Research, and Creality.^[6] Klipper firmware, developed in 2016, has rapidly gained popularity among prosumer FDM 3D printer users.^[7]

Both Marlin and Klipper are published under the GNU General Public License. The GPL requires that users be provided with source code upon request and permits unlimited modification and redistribution.^[8] This licensing structure permits users to compile and flash custom firmware versions without restrictions, which places them in direct conflict with the text of the bill.

HB 2321 would require 3D printers sold in Washington after July 1, 2027 to be equipped with "blocking features" defined as "a software controls process that deploys a firearms blueprint detection algorithm." According to the bill text, these features must "identify and reject print requests for firearms or illegal firearm parts with a high degree of reliability and cannot be overridden or otherwise defeated by a user with significant technical skill."^[2]

The bill defines "firearms blueprint detection algorithm" as a system that evaluates STL files, CAD files, or G-code to determine whether they match firearm designs.^[2] Manufacturers may comply through three methods specified in Section 6(2) of the bill: integration of the algorithm in the printer's firmware, integration in preprint software, or a handshake authentication design between software and printer.^[2]

The bill defines "three-dimensional printer" to include devices capable of both additive manufacturing and subtractive manufacturing from a digital file. This broad definition has been interpreted by commentators to potentially include CNC mills, lathes, laser cutters, and water jet cutters.^[2][9]

Section 3(3) grants the Washington Attorney General authority to "adopt rules and regulations for any other processes the attorney general deems necessary to carry out the provisions of this chapter."^[2] Section 8 requires the Attorney General to create and maintain a database of firearms blueprint files by August 1, 2026, and to update this database at least once per year. Section 7(4) authorizes the Attorney General to adopt rules "requiring developers and users of such algorithms to update such algorithms if new technology is found to be substantially more effective."^[2]

Violations by corporations constitute a Class C felony with penalties of up to five years imprisonment and $15,000 in fines. Violations by individuals are classified as misdemeanors or gross misdemeanors depending on severity. Filing a false attestation constitutes perjury. Violations are also treated as unfair or deceptive acts under Washington's Consumer Protection Act.^[2]

The bill exempts 3D printers sold to entities holding federal firearms manufacturing licenses.^[2]

Governor Kathy Hochul announced comparable proposals on January 7, 2026, as part of her 2026 State of the State agenda. Her proposals would require manufacturers to include blocking software on 3D printers sold in New York, criminalize unlicensed possession or distribution of firearm CAD files, and mandate reporting of recovered 3D-printed guns to state police databases.^[10]

Hochul stated:

"We will require all 3D printers sold in the State of New York to include software that blocks the production of guns and their components. You cannot sell one of those in the State of New York when we pass these laws."^[11]

Governor Hochul has termed the proliferation of homemade weapons the "Plastic Pipeline."

Manhattan District Attorney Alvin Bragg has sent letters to multiple 3D printer manufacturers requesting voluntary adoption of blocking software.

On March 26, 2025, Bragg sent a letter to Shenzhen Creality 3D Technology Co., Ltd. demanding installation of detection software, removal of CAD files from Creality Cloud, and a user agreement ban on weapon creation. The letter explicitly cited the alleged assassination of UnitedHealthcare CEO Brian Thompson by Luigi Mangione, who allegedly utilized a 3D-printed ghost gun, as well as local cases involving defendants using Creality printers (specifically the Ender 3 series) to manufacture arsenals.^[12][13] Bragg's letter specifically recommended a program called "3D GUN'T" developed by Print&GO as an example of existing detection technology.

Bragg sent a similar letter to Bambu Lab in 2025. Reports indicate that some digital design firms have agreed to block content in response to these letters.

No commercially validated firearm detection technology exists for 3D printers as of January 2026. 3DPrinterOS announced a partnership with Montclair State University's MIX Lab in November 2024 to develop an algorithm capable of identifying 3D printed firearm components based on unique design signatures.^[14] Critics argue that algorithms designed to detect "gun shapes" will inevitably generate false positives, flagging harmless objects such as plumbing pipes, L-brackets, or legitimate mechanical parts that share geometric similarities with firearm components.

The bill's requirement that blocking technology "cannot be overridden or otherwise defeated by a user with significant technical skill" presents a challenge given the open-source firmware landscape. Users can download Marlin or Klipper source code, remove any blocking code, and flash the modified firmware to their printers. The GPL license requires manufacturers using Marlin-based firmware to provide source code upon request.^[15] 

The question of whether computer code constitutes protected speech under the First Amendment remains partially unresolved. In 2016, during the Defense Distributed v. U.S. Department of State litigation, the Fifth Circuit declined to rule on the merits of the First Amendment claims, instead deciding the preliminary injunction on non-merits requirements. In her dissent, Judge Edith Jones wrote that the State Department "barely disputes that computer-related files and other technical data are speech protected by the First Amendment."^[16]

The case settled in July 2018 with the State Department waiving prior restraint against Defense Distributed and paying approximately $40,000 in legal fees. State Department spokesperson Heather Nauert stated the government "would have lost this case in court, or would have likely lost this case in court, based on First Amendment grounds."^[17]

The Electronic Frontier Foundation filed an amicus brief in the Defense Distributed litigation arguing that "publishing computer files that communicate information, even in an esoteric format, is speech protected by the First Amendment."^[18]

Earlier circuit court precedent supports code as speech. In Bernstein v. U.S. Department of Justice (N.D. Cal. 1996), U.S. District Judge Marilyn Hall Patel found "no meaningful difference between computer language... and German or French."^[19]

Federal law permits individuals to manufacture firearms for personal use without a license, provided weapons comply with the Undetectable Firearms Act. The Bondi v. VanDerStok decision did not address whether mandatory blocking technology infringes on manufacturing rights, as plaintiffs in that case raised no Second Amendment claims. According to The Regulatory Review, courts have been "generally unreceptive to the argument that the Second Amendment of the U.S. Constitution guards against restrictions on the right to acquire firearm parts for self-assembly."^[5]

The NRA Institute for Legislative Action criticized the proposals as having "First and Second Amendment implications" and characterized device-level blocking as creating concerns about prior restraint on speech. The organization stated: "All citizens should be gravely concerned with unconstitutional prior restraints on free speech when government works to require private companies to monitor and censor information on what citizens in most jurisdictions are legally allowed to create and possess in their own homes."^[20]

In January 2025, Bambu Lab announced "Authorization Control" for its X1 series printers, introducing authentication for operations including firmware upgrades, print job initiation, and remote video access. The company cited security concerns including cyberattacks and DDoS attacks as motivation for the change.^[21]

Third-party software including OrcaSlicer faced disruption. OrcaSlicer developer SoftFever publicly declined to adopt "Bambu Connect", calling it "unnecessary and of no meaningful benefit to users."^[22] Josef Prusa, CEO of Prusa Research, commented on LinkedIn: "Quite scary where the 3DP industry is moving – control of your data."^[21]

In November 2025, Creality published a "Root Disclaimer and Risk Warning" stating its 2025 K1 Series "no longer supports Root access." Original K1 models had shipped with root access available through the settings menu. Creality's disclaimer stated that root access introduces security risks, including potential exposure of user information and privacy data through unauthorized applications.^[23]

No country has mandated device-level firearm blocking technology in 3D printers.

In the United Kingdom, MP Preet Kaur Gill introduced the Firearms (3D Printing) Bill in October 2024. Clauses 43-44 of the Border Security, Asylum and Immigration Bill, introduced in January 2025, would criminalize making, importing, and possessing "templates" (blueprints) for 3D-printed firearms with up to 5 years imprisonment.^[24][25]

Australian states have enacted penalties for possessing digital firearm blueprints. Tasmania criminalized the possession of digital blueprints for the manufacture of firearms, with penalties of up to 21 years imprisonment. New South Wales imposes up to 14 years imprisonment under Section 51F of the Firearms Act 1996. South Australia has proposed penalties of up to 15 years imprisonment.^[26]

The European Union regulates possession of 3D-printed firearms under EU Directive 2021/555, but possession of digital blueprints is not explicitly prohibited.^[27][28]

As of January 21, 2026, HB 2321 has completed first reading and remains in the Civil Rights & Judiciary Committee. No hearings have been scheduled.^[29]