When you think of silk, you think of that incredibly soft, hyper-slick material that, when used as a fancy pillowcase to keep your hairdo intact, can make your head slide clean off the thing in the middle of the night, immediately making you question whether spending $75 on a single pillowcase was some kind of wellness-industry scam.

Humans have been extracting silk from silkworms for thousands of years, and now, according to researchers from Tufts University, Imperial College London, and the University of Michigan, the super soft, sleek, and luxurious material may have a secondary use as super tough body armor.

In a new study published in Nature Sustainability, researchers found a way to transform silk fibers into a tough-as-nails material durable enough to be considered somewhere in the neighborhood of Kevlar’s toughness. Pretty cool for a material that we normally associate with rich people pajamas.

The Science Behind Creating a Supermaterial With Silkworm Silk

Instead of dissolving silk down with chemical-heavy processing like scientists usually do, the team kept the fibers intact. They aligned them in one direction and subjected them to carefully controlled heat and pressure. If you apply too little pressure, the material remains weak. Too much and it starts to become brittle. But if you find the sweet spot, a temperature range of 257 and 419 degrees Fahrenheit, and keep the pressures hovering around 9800 atmospheres, then those fibers start to fuse to form a dense, transparent solid material that’s nearly as tough as Kevlar, the material lining bulletproof vests.

The researchers say they can withstand ballistic impacts, but it’s also biocompatible enough to be used for medical devices, like the screws, pins, and plates people get bolted into, say, rickety knees or a fractured skull. It can also potentially be used as a component in communications systems.