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
Bruce foil a downwards force. Bruce foils can be mounted in pairs, one on each side, as used in some trimaran designs. In this case, the leeward foil works in conjunction with the leeward ama to provide lift, and the windward foil can be retracted to reduce drag. At equilibrium, the force from the foil and the sail will always be balanced, so capsize should be impossible, but in practice that is not the case. Since the foil's force is relative to the hull's movement through the water, and the sail's force is relative to the wind moving past the sail, sudden