Abrasive substances of the 'organic' category consist of fibres, which can be gained from glas, rubber, carbon or Kevlar and Twaron. Furthermore, they consist of fillers and temperature-resistant synthetic or natural resin. These coverings are said to be softer, quieter, but they also have the reputation of fast wear and brake dust development. On top of that, especially after increased temperature levels, they develop a worse reaming performance. They are designed for the hobby and entry-level field.