A new material has been developed which is said to be both lighter than water, and stronger than steel.
The bone-like stuff was created by Jens Bauer at the Karlsruher Institute of Technology, according to Phys.org.
The reason it's so interesting, is that materials which are less dense than water - such as wood and bone - are porous, but are generally less strong than denser materials.
Theoretical studies and mathematical models have shown that it's possible to find a better balance between strength and density, with patterns on the scale of a human hair. But actually building them seemed impossible.
But using Nanoscribe 3D printers, the German team was able to make a new material which is both porous and extremely strong, based on that research.
"This is the first experimental proof that such materials can exist," he said.
The technique is complex, involving removing areas of polymer with a computer-aided laser, then adding aluminium oxide and submitting materials to stress tests.
Bauer's best result is stronger than all natural and man-made materials lighter than 1000kg/m3, and is as strong as some types of steel. Of course, making it in bulk is still a long way off - and this particular material won't be replacing traditional materials.
But the more work that is done in this area, the more likely it is that one day we'll be printing the stuff our homes are made with - if not our homes themselves.