Loading your Ultralight pack is a learned skill that will greatly improve your comfort during a hike
Going ultralight is as much about knowledge as it is about gear. That's one reason we always recommend buying your pack last, after you know what's going inside.
There are a few tricks to properly packing a frameless bag in order to give it structure and the level of comfort that you're looking for as an ultralight hiker. Given that we're launching the Kiwi Ultralight Tui 42L pack in the next few weeks, we want to make sure you know how to make the most of the experience! (Update: Get your Tui 42 here!)
You can think of your pack in terms of zones that need to perform a certain function:
1. The bottom of the pack contains your bulk. We recommend stuffing your quilt down into the pack liner's bottom first, then your spare clothing, your fitted sheet or silk liner, etc. Being at the bottom both puts the bulk under a bit of compression, plus it raises up the middle zone of the pack.
2. The middle zone provides most of the structure in a frameless pack and contains the heaviest items. This is where you would stack (usually horizontally, but vertically also works depending on the specific gear) your tent, food bag, and sleeping pad. Try to make a flat surface against your back using these items - this is critical for comfort and stability. That means keeping your cooking gear away from your body. This zone may include some items inside the liner, and some outside of it depending on preference.
3. The top of the interior pack is used for things that need to be kept waterproof yet easily accessible during the day. This may include a thermal layer and a dry bag with electronics, headlamp, first aid, etc.
4. Finally, the external pockets are great things you use while walking. Snacks, sunblock, a hat, sunglasses, your phone, rain gear, water filter, etc. Most ultralight hikers use water bottles, but those who want to use hydration bladders often keep them in the center pouch and run the line under their arm up to an attachment on the chest harness.
What we recommend avoiding
Tents and quilts/sleeping bags on the outsides of packs. This leads to more wear and alters the balance of the pack.
Quilts in compression sacks. Instead, just loosely stuff bulky items into the bottom of your pack liner. The quilt will still compress, but will also fill space more efficiently rather than leaving a hard lump in your pack (not to mention it's lighter).
Exceeding weight limits. These need to be taken seriously, use a different pack on trips where you are packing heavier than the manufacturer's recommendations. You will feel it more in a frameless pack if you exceed the design.
The goal with a frameless pack is to use your gear itself as a frame. The tighter you pack the kit, the more weight transfer you will get from the shoulders to the hips. Learning to do this properly, and reducing your carried weight as much as possible, will give you the most comfortable backpacking experience possible - this is what all ultralight hikers strive for.