Pack in. Pack out. Any responsible outdoor person…
Source: I combine 3 things
Pack in. Pack out. Any responsible outdoor person does it. But nobody likes a bulky, smelly trash bag that may get pierced inside their backpacks. I decided it was time to figure out something better: combine 1 4-liter dry sack, 1 small trash bag, 1 small roll of tape. Enough for two persons on a 6-day trek.
While preparing for walking the Overland Track with my daughter last November, I found myself trying to choose between a relatively heavy, large, and durable trash bag and a super light, smaller and flimsy one. From experience I knew that both very soon would make for a bulky bag in my backpack and that I would be worried about them leaking smells at the best and moisture at the worst.
I decided that there should be a better solution. Surfing on the internet I found the Sea to Summit Trash Dry Sack, but with 100 g that definitely was too much for a gram-saver like me. And 10 liters also seemed more than necessary.
I knew I needed something similar. I already had a 4-liter Sea to Summit Ultra Sil Nano dry sack. I bought the smallest possible trash bags I could find at my supermarket. They turned out to be 5L, brand Swirl. And I added a small role of leukopor, which is a very thin variant of leukoplast.
This last piece of equipment is essential to keep the volume low. Simply roll or fold everything that goes in the trash bag as small as possible and apply tape to keep it that way. As you probably already figured out the trash bag goes in the dry sack. The trash bag can easily be closed with a knot. Then press most of the air out of the dry sack and close it as indicated.
Of course any tape will do. With leukopor I used quite a lot to wrap it around our empty meal packages and wrappers. If you are carrying leukoplast to tape against blisters and for first-aid uses, why not use some of that. It's heavier than leukopor, but sticks better too and does a better job in case of moisture, so less is needed.
We started out with 19 g (dry sack) + 2x2 g (2 Swirl trash bags, 1 spare) + 5 g (tape) = 28 g.
Back in the inhabited world, after six days on the Overland track, I happily disposed of 1 full Swirl trash bag.