Thisbook,entitledLowThermal Expansion Glass Ceramics,isoneofaseries reporting on research and development activities on products and processes conducted by the Schott AG. Thescienti?callyfoundeddevelopmentofnewproductsandtechnicalp- cesses has traditionally been of vital importance at Schott and has always been performed on a scale determined by the prospects for application of our special glasses. The scale has increased enormously since the reconstruction of the Schott Glaswerke in Mainz. The range of expert knowledge required for that could never have been supplied by Schott alone. It is also a tradition in our company to cultivate collaboration with customers, universities, and research institutes. Publications in numerous technical journals, which since 1969 we have edited to a regular timeplan as Forschungsberichte – ‘research reports’–formedthebasisofthiscooperation.Theycontainup-to-dateinf- mation on various topics for the expert but are not suited as survey material for those whose standpoint is more remote. This is the point where we would like to place our series, to stimulate the exchange of thoughts, so that we can consider from di?erent points of view the possibilities o?ered by those incredibly versatile materials, glass and glass ceramics. We would like to show scientists and engineers, interested customers,andfriendsandemployeesofour?rmtheknowledgethathasbeen won through our research and development at Schott in cooperation with the users of our materials.