Paper corner guards are usually not waterproof. Paper corner protectors are decorative or protective materials used to protect the corners of paper or paper products, usually for binding the corners of books, folders, or other paper products. They are typically made from cardboard, cardboard, or plastic and are designed to enhance the paper's durability and prevent corners from being frayed or damaged.

If you need waterproofing features, such as protecting paper documents or materials from moisture, you may want to consider using waterproof folders, plastic sleeves, or other packaging materials with waterproof properties. These materials better protect your documents or paper from water, liquids or humid environments.