Contents: (Small 10/2014)

On page 1902, G. Zabow and co-workers introduce a new, simple approach to transform microspheres into almost mathematically exact ellipsoids and ellipsoidal shell particles. Micro-ellipsoids are increasingly valued for unique packings and selfassemblies of anisotropic materials, but hollowed-out ellipsoids can also generate uniform local electromagnetic fi elds, a feature unexploited until now. Demonstrating their utility, the hollow ellipsoids are used to controllably tune the NMR frequencies of surrounding water molecules, enabling also a new form of multispectral MRI agent.