Elastomers and rubberlike materials form a critical component in diverse applications that range from tyres to biomimetics and are used in chemical, biomedical, mechanical and electrical engineering. This updated and expanded second edition provides an elementary introduction to the physical and molecular concepts governing elastic behaviour, with a particular focus on elastomers. With a list of experiments and demonstrations, problem sets and solutions, this is a self-contained introduction to the topic for graduate students, researchers and industrialists working in the applied fields of physics and chemistry, polymer science and engineering.