Poly mailers are a type of shipping envelope made from a combination of polyethylene and other materials. They are known for their lightweight, water-resistant, and tear-resistant properties. Poly mailers are an excellent option for shipping non-fragile items such as clothing, books, or other soft goods. However, when it comes to fragile items like electronics, glassware, or delicate ornaments, poly mailers alone may not be sufficient to protect them from damage during transit.