Several years ago, scientists calculated the properties of an exotic form of carbon—called Carbyne—and found that it promised more strength and stiffness than any other known material. Now, it’s finally been made in a stable form inside an Austrian lab.

Researchers from the University of Vienna in Austria report in Nature Materials that they’ve managed to syntehesize the material far more successfully than ever before. It’s proved so tricky in the past because Carbyne is a long one-dimensional chain of carbon atoms linked one to the other. Its structure makes it highly reactive, which means that as quickly as it’s manufactured, it’s destroyed.

But the Austrian researchers have found a way to make it while avoiding such destruction. They took two sheets of graphene, laid them on top of each other, then rolled the whole thing up to create a double-walled tube. Think of it as a graphene Thermos. Then, they synthesized the Carbyne inside the tube, providing a protective casing which allowed the material to remain in tact.

The record for stringing together carbon atoms like this in the past had been 100 in a row; now, the team can put 6,400 atoms together, and have them remain in a chain for as long as they want. That is, of course, as long as they sit inside the carbon Thermos. It remains to be seen how useful Carbyne will be whilst wrapped up, but for now it’s the best that researchers can achieve.

Regardless, other researchers will doubtless clamour to try and exploit the newly produceable material: Previous calculations have shown that Carbyne is stronger than both graphene and diamond, and around twice as stiff as the stiffest known materials. That sounds pretty promising to us.