Aluminium foil decoration, and crafts, especially in bright metallic colours. Metallic aluminium, normally silvery in colour, can be made to take on other colours through anodisation. Anodising creates an oxide layer on the aluminium surface that can accept coloured dyes or metallic salts, depending on the process used. In this way, aluminium is used to create an inexpensive gold foil that actually contains no gold, and many other bright metallic colours. These foils are sometimes used in distinctive packaging. Foil is used by organic/petroleum geochemists for protecting rock samples taken from the fields and in the labs where the sample is subject
Tin foil hat telepathy. Some people have a belief that such hats prevent mind control by governments, spies, or paranormal beings that employ ESP or the microwave auditory effect. People in many countries who believe they are "targeted individuals" (TIs), subject to government spying or harassment, have developed websites, conference calls, and support meetings to discuss their concerns, including the idea of protective headgear. Over time the term "tin foil hat" has become associated with paranoia and conspiracy theories. The notion that a metal foil hat can significantly reduce the intensity of incident radio frequency radiation on the wearer's brain has some scientific