We get asked this a lot and it’s a difficult question to answer. The padding we use is a polyester fiber fill, similar to what you’d find inside a sleeping bag or quilt. The padding is quilted to a tough but soft nylon lining. The standard padding is about 3/8″ thick and the double is closer to 3/4″ thick. We make double padded bags and covers for customers because they; 1) are hard on their gear, 2) they want the best protection for their gear, 3) someone else is handling their gear. Single padding works great. Double works better. Double padding has twice the fiber fill that single pad has. It’s not something you can easily see (the double pads aren’t puffy), but you can feel the difference. More fiber is more shock absorbance.