Q: What is hot foil stamping? A: Hot foil printing, also known as gold blocking or hot foil blocking, is a method used to transfer an image through the application of heat and pressure on to a product that requires decorating. Foil comes in a vast range of colours and finishes which can be gloss, matt, metallic, pearl and marble. Rainbow patterns and even wood grains can be achieved. Foils also come in pigmented colours and special effects including holographic patterns such as those seen on many credit cards.