The invention concerns a reinforcing agent which can be used as fillers for duroplastics and thermoplastics which reinforce isotropically in two dimensions parallel to the component surfaces and whose reinforcing effect complements that of the other isotropically reinforcing fillers for duroplastics and thermoplastics. According to the invention, the reinforcing agent consists of particles whose length: width ratio is approximately 1, whose material thickness is less than the width, whose content in the plastics - relative to the reinforced plastics - is between approximately 10 and approximately 50 wt %, and whose surface is structured with reliefs.
