A FEDERAL judge in Seattle has issued a temporary restraining order to stop the release of blueprints to make untraceable and undetectable 3D-printed plastic guns.

Eight Democratic attorneys general filed a lawsuit on Monday seeking to block the federal government’s settlement with the company that makes the plans available online.

They also sought a restraining order, arguing the 3D guns would be a safety risk.

The company behind the plans — Defense Distributed — had reached a settlement with the federal government in June that allows it to make the plans for the guns available for download on Wednesday.

The restraining order puts that plan on hold for now.

At a news conference on Tuesday, Democratic senators said US President Donald Trump has the power to stop the company from making the plans available online.

The company’s website says downloads have been posted on the site since Friday.

A lawyer for the company said he doesn’t know how many blueprints have been downloaded since then.

People can use the blueprints to manufacture plastic guns using a 3D printer. But industry experts have expressed doubts that criminals would go to the trouble.

Printers needed to make the guns are very expensive, and the guns themselves tend to disintegrate quickly.

Unlike traditional firearms that can fire thousands of rounds in a lifetime, the 3D-printed guns normally last only a few rounds before they fall apart, experts say.

THE MAN BEHIND THE 3D-PRINTED GUNS

Cody Wilson, a self-proclaimed “crypto-anarchist” and gun rights advocate, is to make the open-source digital files for making so-called “ghost guns” available for download.

Mr Wilson first published downloadable designs for a 3D-printed firearm in 2013, before the US State Department ordered him to cease.

It’s believed the plans were downloaded about 100,000 times, contending the effort violated federal export laws since some of the blueprints were downloaded by people outside the United States.

The State Department reversed course in late June, agreeing to allow Wilson to resume posting the blueprints.

The company filed its own suit in Texas on Sunday, asserting that it’s the victim of an “ideologically fuelled program of intimidation and harassment” that violates the company’s First Amendment rights.

Amid last-minute legal manoeuvres to stop Mr Wilson, US President Donald Trump weighed in on the debate, revealing that he had spoken to America’s main pro-gun lobby, the National Rifle Association, about the topic.

“I am looking into 3-D Plastic Guns being sold to the public,” Mr Trump said, in apparent scepticism about their use.

“Already spoke to NRA, doesn’t seem to make much sense!

In June, after a five-year legal battle between Mr Wilson and the federal government, Mr Trump’s administration granted him permission to operate his website Defcad, envisioned as the WikiLeaks of firearms.

Mr Wilson, who has called gun control “a fantasy”, told The Washington Post that the government’s efforts to stop him from publishing the computer code needed to build 3D-printed guns was akin to stifling free speech.

“[Code] is the essence of expression,” he told the newspaper. “It meets all the requirements of speech — it’s artistic and political, you can manipulate it, and it needs human involvement to become other things.”

But eight states filed a federal lawsuit on Monday in a last-minute effort to stop Mr Wilson, saying the issue is one of public safety.

Politicians, gun control advocates, and members of law enforcement expressed concerns that anyone — from a teenager to a convicted felon — could make untraceable weapons, including plastic ones that could evade metal detectors.

The technology presents Mr Trump with tough questions about protecting the public, the limits of gun ownership rights and his own political fortunes.

Democrat Nancy Pelosi, the minority leader in the US House of Representatives, condemned the administration’s settlement that will allow Mr Wilson’s website to go live on Wednesday, barring further court action.

“This decision is a death warrant for countless innocent men, women and children,” Ms Pelosi said in a statement. “For the sake of all our safety and lives, it must be reversed immediately.”

Senate Democrats introduced legislation today to prohibit blueprints for 3D printed guns from being posted online.

But it’s unlikely that Congress will take action before the midnight deadline.

Earlier in July, Los Angeles police showcased an arsenal of so-called “ghost guns” seized from gang members during a six-month undercover operation.

The weapons, including AR-15-style semiautomatic rifles, were fashioned from kits purchased online, according to police. Mr Wilson’s website will also feature blueprints for AR-15-style arms.

In the five years since his legal battle began, Mr Wilson’s company Defence Distributed has grown to 15 employees inside a nondescript warehouse in the Texas state capital of Austin.

HOW DO 3D PRINTED GUNS WORK

The most common type of 3D printing is the process called Fused Deposition Modelling (FDM), and this is the technology used to make the handful of working 3D printed guns that have been made.

It works by slicing a digital file into hundreds of thin layers, often about 0.1mm thick.

The 3D printer will then use robotic precision to place these layers on top of each other to replicate the item it is printing ie a physical copy of the digital file.

This can take several hours.

The 3D printer works with melted thermoplastics, or liquefied plastic, so it can’t print off a complex mechanism like a functional gun all in one piece.

Instead, each separate component of the gun needs to be 3D printed individually and then later assembled.

It becomes even harder if any of those parts has an overhang of more than about 45 degrees. It makes 3D printing a functional gun very time consuming and difficult but not impossible.

Many of these guns will also fall apart after firing a single shot due to the explosive force involved.

High-end 3D printers needed to make such weapons can be very expensive as well, often costing thousands of dollars, meaning it would often be more expensive then actually buying a gun in the US.