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
Cold foil printing spools from an unwind and is nipped to a substrate. Foil sticks to the tacky adhesive on the substrate, and an image with a bright foil surface is created. Foil that does not adhere to the adhesive remains on a thin polyester liner, and waste is directed to a rewind spool. Because the adhesive is applied on press like a conventional ink, no expensive stamping die has to be created. Once printed, the surface of cold foil images may be varnished, laminated, or encapsulated in order to provide a hard-wearing, durable surface. Some printing substrates are unsuitable for cold foil