Aluminium foil 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. The continuous casting method is much less energy intensive and has become the preferred process. For thicknesses below , two layers are usually put together
Cold foil printing transfer. The best results are obtained on glossy coated papers and papers with a smooth surface. Weights from about 80 to 500 g/m^2 are possible. The process does not require stamping tools, but instead uses printing plates, which are cheaper and can be made in a few hours. In contrast, delivery time for an engraved or etched stamping tool can be up to two weeks. More importantly for the designer, gradients and halftone images can be introduced. Cold foil evolved from hot foil stamping. Hot foil stamping is mostly used offline when foil is required on a preprinted substrate, such