The book deals with the physical and chemical modification of natural and synthetic fibres for technical applications. Natural fibres and synthetic fibres/ filaments are often inadequate to be used in technical textiles. The high level of moisture absorption of natural fibres, poor wettability by non-polar plastics, and insufficient adhesion between untreated fibres and the polymer matrix, result in poor properties in composites. Synthetic fibres often lack the required mechanical and thermal properties to be used for technical applications. The book will thus encompass methods to physically and chemically modify fibres for technical applications.