These were being trialed when I was a medic 20 years ago. Being foam they are light and conform well to what your bandaging.
I used to carry about 20 of them in my pack and the total weight was negligible.
Absorbent Foam Bandage | Wound Care Dressing | Andover CoFlex AFD
If you really want to get serious about first aid you could also carry sterile saline solution. If someone gets hurt and become unconscious you can infuse fluid rectally.
Each of the British soldiers on the ground in the Falklands carried one liter of fluid in their packs. When a soldier got shot they would dress the wound then insert a plastic tube into the soldier rectum and open up the valve.
It worked extremely well. Their survival rate was the highest ever for British soldiers.