Gutta percha

Acronym and details:   A hard substance exuded from tropical tree that softens in hot water

Group:   thermoplastic

Developed:   introduced from Far East in1843; wide range of products shown at 1851 Great Exhibition, London; use falls off in 1930s

Trade names: 

Manufacturing process:   compression moulding; extrusion

Cost:   low

Colour:   dark, but sometimes painted

Transparency:   always opaque

Rigidity:   normally rigid

Feel:   old material is hard; modern gutta percha is often softer; dry-ish

Smell:   none

Other:   can look woody

Typical uses:   golf balls; dentistry; insulation for submarine telephone cables; household uses similar to those of tin; fancy mouldings

Degradation:   oxidises and embrittles, as a result mouldings are now scarce