40oz Choc/Gold Stanley Dup with Custom Cowgirl Design and Custom Boot Custom design is laser engraved on this Stainless Steel mug! Laser engraving is a non-contact process that uses a focused laser beam to vaporize a material's surface, creating a permanent mark. The durability of a laser engraving can exceed 30 years, and in many cases, it is permanent. On materials like stainless steel, aluminum, or titanium, engravings can last for the entire lifetime of the item without noticeable wear