On May 13th 2011, the journal Science publishes a paper where scientists from Risø DTU in collaboration with scientists from China and USA, report a new method for revealing a 3D picture of the structure inside a material. Most solid materials are composed of millions of small crystals, packed together to form a fully dense solid. The orientations, shapes, sizes and relative arrangement of these crystals are important in determining many material properties. Traditionally, it has only been possible to see the crystal structure of a material by looking at a cut surface, giving just 2D information. In recent years, x-ray methods have been developed that can be used to look inside a material and obtain a 3D map of the crystal structure. However, these methods have a resolution limit of around 100nm (one nanometer is 100,000 times smaller than the width of a human hair).