What gives materials strength are the defects within. In order to connect the structural properties of the material of interest with the internal microstructure, it is required to characterize the materials on all length scales regarding, for example, the grain size, texture, chemical composition, and atomic interface structure. This is achieved by use of a broad range of characterization facilities spanning optical methods, scanning and transmission electron microscopes, atomic force microscopy, and x-ray techniques. Selected examples are shown below.