Boundary Supply Errant Pack Review
This pack arrived in October 2023 in Obsidian Black and has been in weekly rotation ever since. Three jobs, mostly: gym bag, commute bag, and daypack on trips. That last one is where it earns its keep, because the same 20 liters works for a hike and for a full day walking around a city without feeling like the wrong tool in either place.
Boundary has since discontinued it and replaced it with the Errant Pack MK II in X-Pac, so if you are shopping new today the MK II is what Boundary will sell you. This generation is still on Amazon while stock lasts, with one caveat worth stating up front: the listing there is the X-Pac fabric edition, while mine is the standard fabric in Obsidian Black. Same pack, same dimensions, different shell, and Amazon rates it 22 liters and a 15 inch laptop where Boundary said 20 liters and 16 inches.
Usability & Features
The main compartment opens flat, clamshell style, so the bag lays open like a suitcase instead of making you dig down a hole. For packing, this is the single best thing about it. You see everything you own at once.
The laptop sleeve is the other standout. A MacBook Pro drops in with room to spare, and something slightly larger still fits. More to the point, the padding is real: I have never once worried about setting the bag down hard with a laptop inside, and after nearly three years of that treatment the laptop has never had a problem. If you carry an expensive machine daily, this is the part that matters.
It flies well. It slides under an airline seat as a personal item without a fight, which is the whole reason it has been on as many trips as it has. Pair it with a carry-on and you are done.
The pocket count is high and, unusually, every pocket has an obvious purpose. Expandable side pocket that swallows a 32 oz bottle, magnetic key dock so keys are not loose in the main bay, RFID-safe hidden pocket, a lined top pocket for sunglasses or a phone, bottom zip pocket, luggage pass-through. Compared to the plainer daypacks I used before this, like the Haglöfs I carried for years, the Errant has far more considered organization and much better laptop protection. Nothing rattles around.
I never bought any of the modular magnetic accessories. This is the bare pack, no Fieldspace insert, no camera case, and it has never felt like it needed them.
Now the annoyance, and there is exactly one. Getting into the main compartment through the front flap is not as quick as it should be. The hook fasteners under the flap are stiff and do not always release cleanly, so what should be a two second grab turns into fumbling. It is the one design decision I would change, and it is the only real complaint I have after three years.
Aesthetic & Design
All black, minimal, with just the small Boundary logo on the flap. It reads as a plain black backpack rather than a piece of technical gear, which is exactly why it moves between a gym, an office, a trailhead, and a city street without ever looking out of place. There is no color, no branding shouting, nothing to date it.
This is also where I part ways with the replacement. The MK II uses brown and beige interior fabric, and I think that is a downgrade. The original's blacked out interior looked better and, frankly, hid grime better too. The MK II is the more advanced bag, but the older one has the better colorway.
Durability & Care
Nearly three years in, the honest damage report is short. The plastic-faced front panel has picked up scratches and some discoloration where it has caught walls, door frames, and whatever else a bag hits when you carry it every week. That is wear I would expect from any bag treated the same way, and it is cosmetic.
Everything functional is intact. Every zipper still runs smoothly. Every magnet still holds. No fraying at the strap anchors, no sagging in the back panel foam, no failed stitching. For a bag that has done gym duty, commutes, and repeated flights, that is a genuinely good record.
The empty weight is 1.41 kg, which is heavy for 20 liters and the usual criticism of this pack. In practice it has never bothered me, because that weight is where the structure and the laptop protection come from. Boundary clearly heard the complaint anyway: the MK II is roughly 30 percent lighter at 1.03 kg, which is the single most convincing argument for the new one.
Final Thoughts
I would buy the MK II when this one dies. The problem with that plan is that this one shows no sign of dying. Nothing on it is close to failing, so the replacement is a hypothetical purchase for a hypothetical future.
It launched at 279 USD and leftover stock currently sits around 309 USD, against 374 USD for the MK II. Paying more for the older, heavier version is a strange sentence to write, so be clear about what the extra 65 USD on the MK II buys you: roughly 30 percent less weight, X-Pac fabric, and a 17 inch laptop sleeve, at the cost of that brown interior. I would still take the original at 309, with the flap fasteners as your one known irritation and the better interior color as your consolation.
Skip it if you want a bag you can rip open one handed at speed, because the flap will annoy you daily. Skip it too if grams matter more to you than structure, in which case go straight to the MK II. But if you want one 20L bag that handles the gym, the commute, the plane, and a trail without needing a second bag for any of them, this shape is still right. It is a different animal from a dedicated travel pack like the Black Ember Forge 40 Max, which is built to be your only luggage for weeks. The Errant is the bag you carry every ordinary day, and it has been doing that here for nearly three years without complaint.
