Baby nappy liner, also known as a diaper liner, is a thin, absorbent material that is placed between a baby's bottom and the nappy or diaper to help protect the nappy from becoming soiled. The liner is typically made from a soft, breathable material, such as cotton or bamboo, and is designed to capture solid waste and prevent it from sticking to the nappy, making clean-up easier and more hygienic. Nappy liners can be disposable or reusable, depending on the material and brand, and are often sold in rolls or packs for convenience. Some nappy liners are also biodegradable or compostable, making them a more eco-friendly choice for parents. Using a nappy liner can help reduce diaper rash and irritation by keeping a baby's skin dry and comfortable, and can also make nappy changes faster and less messy.