The term signifies a base metal item that has been coated with a thin layer of gold. The ’18k’ specifies the purity of the gold used in the plating process, indicating that it is composed of 75% pure gold mixed with other metals. The application of this gold layer is typically achieved through electroplating, where a thin deposit of gold is bonded to the underlying metal. As an example, a watch made from stainless steel might have a surface treatment of this kind to give it the appearance of being made of solid gold.
This application is frequently implemented to offer the aesthetic appeal of gold at a lower cost than producing an item entirely from solid gold. The process enables manufacturers to create more affordable products while still providing a visually appealing gold finish. Historically, this technique has allowed for broader accessibility to gold-toned jewelry and decorative objects, making them more attainable to a wider range of consumers. However, its long-term durability and resistance to wear are less than that of solid gold items.