Sony NEX 7 + MC MIR 35mm f2.0
Vulcanization or vulcanisation is a chemical process for converting rubber or relatedpolymers into more durable materials via the addition of sulfur or other equivalent “curatives.” These additives modify the polymer by forming crosslinks (bridges) between individual polymer chains.[1] Vulcanized material is less sticky and has superior mechanical properties. A vast array of products are made with vulcanized rubber including tires, shoe soles, hoses, and hockey pucks. The process is named after Vulcan, Roman god of fire. Hard vulcanized rubber sometimes sold under the brand names ebonite or vulcanite, and is used to make hard articles such as bowling balls and saxophone mouth pieces. – Princeton University
The Digital Painter 