The Paxis backpack with swing around section looks perfect for letterboxing, but it is over $200 and almost always in "sold out" status.

What do you use to go letterboxing? A backpack? A totebag?

I bought a lunch box at Walmart last year that has two pockets, one I use for my log books and the other for ink. It works great. If I'm on a long trail, or want to extend my search into a hike, I put it in my daypack.

I have used a messenger style bag before and liked it as well.

Over the years I have used a standard backpack, a backpack with an attached folding seat, a camera bag, a dvd bag, a waist pack, a fanny pack, a messenger bag, a child or husband to wear said various packs for me, and after 18 years I have finally found the perfect letterboxing bag and nowadays they are quite common - a cross body front pack like this

Warrior Woman
your mileage may vary

I prefer a day pack, it allows me to carry a water bladder, blue foam sit pad, rain gear, bug dope/sunscreen, a small first aid kit for me, a larger one for injured 'boxes, and my log book(s), stamp(s), clues and ink(s).

I've used a variety of day packs over the years, but I finally found one that I really like. The Marmot Kompressor Plus. It is LIGHT, but not flimsy. No, it is not water proof, or even resistant, and I've never had a bag that was 100%, either. So line it with a trash bag or two, and it keeps everything secure, and dry. And I've tested it... :-D
https://www.marmot.com/kompressor-plus/24940.html

My current daypack is from Northface. This one is very close to what I have:

https://www.thenorthface.com/shop/equipment-backpacks/borealis-nf0a3kv3?variationId=6VC#hero=0

I have an large size logbook and put it in the laptop pouch.

Got a Bagobago backpack with builtin seat
https://www.amazon.com/BagoBago-Backpack-Build-Seat-Grey/dp/B01KKJR69S
from my boxing daughter. While I wish its capacity was just slightly larger, it actually works really well... gives me an instant seat wherever I go while stamping in.

This is what I use and about a handful of boxers here in the NW. I started a trend!
🤣
https://www.cheaperthandirt.com/product/utg-multi-functional-tactical-messenger-bag-dark-earth-4712274526631.do?sortby=ourPicks&refType=&from=fn&ecList=7&ecCategory=119742

It's awesome and easy to use.

I use a fanny pack, shifted to my waist on the right side. However, when I go to plant boxes, I need a small pack.

We just use one of those drawstring bags.

I like it!

We use a small cross-over bag for the logbook, stamp pads, and a set of markers......for easy and quick access. We also carry a small backpack with other things we might need such as extra baggies, hand wipes, and old washcloth for wiping the moisture out of a box, garbage bag to kneel or sit on if the ground is wet, bandaids, water and granola bars.

A few years ago some letterboxers were using travel vests or fishing vests that have many pockets. We tried fishing vests and they worked great....the only problem was that other people on the trail would assume we worked at the park and ask us questions we couldn't answer. Also..don't wear them when it is not fishing season or there isn't a river or lake around LOL (too many questions) I think the travel vest might work better. :)

Drawstring backpack with of course the WVU logo.