K18GP, or 18-karat gold plated, refers to jewelry or items that are made from a base metal and coated with a layer of 18-karat gold. The "18K" indicates that the gold content is 75% pure gold, while the "GP" stands for "gold plated," meaning the item has a thin layer of gold applied to it. This process allows for a more affordable alternative to solid gold while still providing the appearance of gold jewelry. However, the gold plating can wear off over time with exposure and use.