<P> In 1911, Bern - based Tobler began wrapping its chocolate bars in aluminium foil, including the unique triangular chocolate bar, Toblerone . By 1912, aluminium foil was being used by Maggi (today a Nestlé brand) to pack soups and stock cubes . </P> <P> The first use of foil in the United States was in 1913 for wrapping Life Savers, candy bars, and gum . Processes evolved over time to include the use of print, colour, lacquer, laminate and the embossing of the aluminium . </P> <P> Aluminium foil is produced by rolling sheet ingots cast from molten billet aluminium, then re-rolling on sheet and foil rolling mills to the desired thickness, or by continuously casting and cold rolling . To maintain a constant thickness in aluminium foil production, beta radiation is passed through the foil to a sensor on the other side . If the intensity becomes too high, then the rollers adjust, increasing the thickness . If the intensities become too low and the foil has become too thick, the rollers apply more pressure, causing the foil to be made thinner . </P> <P> The continuous casting method is much less energy intensive and has become the preferred process . For thicknesses below 0.025 mm (1 mil), two layers are usually put together for the final pass and afterwards separated which produces foil with one bright side and one matte side . The two sides in contact with each other are matte and the exterior sides become bright; this is done to reduce tearing, increase production rates, control thickness, and get around the need for a smaller diameter roller . </P>

When did tin foil change to aluminum foil