Everything-proof your mattress. Keep your mattress looking and feeling brand new by guarding against dirt, spills, and normal wear and tear. The best mattress protectors match utility with comfort. You don~t want anything that squeaks or smells, but you need a quality mattress protector that actually protects you and your bedding. To meet these standards, a waterproof mattress cover should use a material that~s liquid-proof and breathable~like Casper~s thermoplastic sheeting. Additionally, full and fitted coverage is crucial. Unlike a waterproof mattress topper, covers need to guard all exposed surfaces (top, sides, and at least partial bottom). We use a clinging stretch design that never slides or shifts, providing maximum waterproof protection.