Hot stamping foil is a process in which anodized aluminum (various colors: gold, silver, black, red, green, etc.) is embossed onto paper or cardboard by heating.
Cold foil is an increasingly popular technology. Cold foil printing, also known as cold foil stamping, is a modern method of printing metallic foil on a substrate to enhance the aesthetics of the final product. This technique uses a thin layer of metal on top of the paper and then prints the ink onto the foil. The metal layer penetrates the ink to give all gloss and reflective qualities.