Hard disk systems have recently encounted a storage density ceiling. Most methods in use today have a limit of a few hundred gigabytes per square inch thanks to perpendicular recording. To try to keep storage density rising, scientists have looked at technologies from holographic storage to molecular polymers, but few have made it past the demonstration stage. In a paper in Nature Photonics this week, researchers describe a way to combine two hard drive writing methods to store data at densities of up to one terabyte per square inch, and suggest the media could be stable up to ten terabytes per square inch.