Aluminium foil with all metallic items, aluminium foil reacts to being placed in a microwave oven. This is because of the electromagnetic fields of the microwaves inducing electric currents in the foil and high potentials at the sharp points of the foil sheet; if the potential is sufficiently high, it will cause electric arcing to areas with lower potential, even to the air surrounding the sheet. Modern microwave ovens have been designed to prevent damage to the cavity magnetron tube from microwave energy reflection, and aluminium packages designed for microwave heating are available. Heavier foils made of aluminium are used for art,
Tin Woodman iron or steel but coated with tin (in order to prevent rusting) is called a "Tin" object, as a "tin bath", a "tin toy", or a "tin can"; thus, the Tin Woodman might be interpreted (in English, at least) as being made of steel with a tin veneer. One passage in "The Road to Oz," by Baum himself, wherein the Woodman attends Ozma's birthday party accompanied by a Winkie band playing a song called "There's No Plate Like Tin," strongly implies that this is the case. Another explanation may be that the Woodman is "chiefly" made of tin, with iron