This book focuses on an increasingly important area of materials science and technology, namely, the fabrication and properties of artificial materials where slabs of magnetized materials are sandwiched between slabs of nonmagnetized materials. It includes reviews by experts on the theory and description of the various experimental techniques such as those using nuclear or electron spin probes, as well as optical, X-ray or neutron probes. It reviews potential applications, such as the giant magnetoresistance, and one specialized preparation technique - the electrodeposition.