Crown caps are metal bottle caps commonly used to seal glass bottles, especially for beverages like beer and soda. They have a crimped edge that securely fits over the bottle's neck, preventing leakage and preserving carbonation. Crown caps are typically made from steel and coated with a layer of paint or plastic to resist corrosion. These caps are often printed with logos or designs, making them a popular choice for branding. To open a bottle sealed with a crown cap, a bottle opener is used to pry off the cap. This simple yet effective design has been in use since the late 19th century.