Coated powders offer a variety of different applications. A general description of heterocoagulation and heteronucleation processes and how they are used to prepare well defined coaled participates will be given as an introduction, Following that part will be a number of practical examples. Essential properties of the powder or the final product can be influenced by a specific coaling layer. Examples are the homogeneous distribution of a second component, the protection of the core material towards a reactive environment, the intentional arrangement of electrically conductive or non conductive outer-layers, hydrophilic or hydrophobic behavior, color effects, or the design of controlled microstructures. The present review article will demonstrate how coaled powders can be used to achieve an improved control of numerous properties in composite material systems.