The abbreviation for aluminium foils — thin rolled sheets that wrap, seal and protect foods from light, oxygen and moisture with near-total barrier performance. They close chocolate bars, lid yogurt pots and line ready-meal trays, and their dead-fold behaviour makes them endlessly convenient in kitchens. Food-contact grades must meet purity and migration standards, and acidic or salty foods can corrode unprotected foil — which is why lacquered and laminated grades exist. Lightweight, recyclable and an excellent barrier, aluminium foil remains packaging’s most versatile metal.