Natural fibers have many advantages: they are renewable, biodegradable and robust. They are more energy-efficient to produce than glass or carbon fibers, are lighter and have better acoustics. Their disadvantage: they absorb water very easily. This impairs their mechanical properties. Fraunhofer researchers have collaborated with their partners to combine a special fiber treatment and a yarn technology: as a result, natural fibers can fully exploit their advantages and be used more widely.