Dyneema aka cuban fiber is my favorite for lightweight bags, although it's not perfect. Comes in many grades down to near tissue paper thin which is great for

Dyneema aka cuban fiber is my favorite for lightweight bags, although it's not perfect. Comes in many grades down to near tissue paper thin which is great for small stuff sacks. Obviously, while impressively strong, the thin grades are weaker than the thicker ones, but still amazing. It doesn't like abrasion, so don't drag it across rocks, easy enough; just set your bag down instead of throwing and dragging it. "Well there are situations when you need to…" just avoid getting into those situations. I found my mini first aid kit bag is wearing thin (it's made of the tissue paper thin white color) so for my next mini first aid kit bag I'll go up one level. Don't use it for something where lack of breathability would cause problems… it's pretty impervious to moisture. For the thinner grades, the thread holes can be a weak spot. Thin bags need to be handled a bit more gently. Thicker grades are brutishly strong.