The most commonly used waterproof bag material and structure actually depends on the specific usage scenario and personal preference. However, without specific personal usage experience, we can give some generally popular material and structure choices, which are usually based on a comprehensive consideration of waterproof performance, durability, portability and versatility.
Material:
Nylon + waterproof coating: Nylon is favored for its high strength, abrasion resistance and tear resistance. Combined with waterproof coating, this material waterproof bag can provide excellent protection in bad weather while keeping the bag light and durable.
TPU (thermoplastic polyurethane): TPU material is not only waterproof, but also has good flexibility and elasticity, which makes it an ideal choice for making high-end waterproof bags (such as diving bags or water sports bags). TPU waterproof bags are generally more durable and resistant to wear and tear.
Structure:
Roll-up design: For scenes that require quick opening and closing and extremely high waterproof performance requirements (such as diving or rafting), waterproof bags with roll-up design are very popular. By rolling up the bag mouth tightly and securing it with a tightening tape, you can ensure that the contents of the bag are completely protected from water.
Well-sealed zippers: For most daily and outdoor travel uses, waterproof bags equipped with high-quality, well-sealed zippers are preferred. These zippers are usually specially treated to enhance waterproof performance and are equipped with waterproof zipper covers to prevent water from seeping in through the zipper gaps.
Internal compartments and pockets: In order to facilitate organization and protection of the contents of the bag, I tend to choose waterproof bags with multiple internal compartments and pockets. These designs can help me better classify and store items such as cameras, mobile phones, wallets, water bottles, etc., and ensure that they will not collide with each other or be damaged during movement.
In summary, if I am a person who often travels outdoors or engages in water activities, I may choose a waterproof backpack made of nylon + waterproof coating, with well-sealed zippers and multiple internal compartments. Such a waterproof bag is both lightweight and durable, and can meet my needs in various weather conditions. However, please note that this is just a hypothetical answer based on general preferences, and in fact everyone's choice will be different.