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Call me a gram weenie…
…but ever since I started getting into ultralight backpacking, I’ve had fun digging up the lightest possible options for every piece of gear on my pack list.
And after making the newbie mistake of buying contractor bags instead of compactor bags and realizing that they were humongous and unnecessarily heavy (3.5 oz per bag? WTF??), I turned my gaze towards lightening my pack liner.
I did some digging and found the following 5 lightweight pack liners that are popular among thru-hikers and ultralight backpackers.
1. Trash Compactor Bags: A Popular Budget Option
Trash compactor bags (NOT contractor bags) appear to be the most popular pack liners.
And it’s easy to see why:
They weigh in at around 2-2.5 ounces. They’re very cheap. And they’ve been thoroughly trail tested — I’ve seen many gear lists of thru-hikers and triple crowners who use compactor bags.
They aren’t the most durable option on the list, but they’re so cheap that once one gets torn or beat up you can just replace it with another.
If you go with trash compactor bags, just be sure to buy the unscented variety lest everything in your pack acquires a clean fresh scent. Also, try to find bags which are at least somewhat see-through — this will make it easier to locate the right piece of gear inside.
2. Nylofume Bags: Tougher & Lighter Than Compactor Bags
At 0.9 ounces per bag, Nylofume bags are the second lightest option on this list and are reportedly more durable than compactor bags.
Though the bottom seam has been known to fail in testing, in the field your backpack will almost always be supporting it. I even read one report of a backpacker that had been using the same Nylofume bag for nearly two years.
Nylofume bags are also transparent which makes it easy to find what you’re looking for without having to dump out all your gear.
You can buy them individually, or you can get them for a fair bit cheaper per bag if you buy in bulk.
Nylofume bags were once hard to come by — their original intent is to protect items from fumigation and thus were mostly carried in bulk on pest control sites — but recently Litesmith, a site that sells ultralight backpacking gear, started carrying them and offering them as singles and 3-packs.
Since then I’ve started seeing them pop up more on gear lists, and they appear to have become one of the most popular pack liners out there.
3. Polyethylene Pack Liners: A Little Pricier But Even More Durable
Because of their price they aren’t as disposable as trash compactor bags — you wouldn’t want to have to replace yours after every trip — but they make up for it with their improved durability.
Since they’re sold by ultralight backpacking gear companies, they’re an ideal size for an ultralight hiker’s pack. And the clear polyethylene makes finding gear a cinch.
4. Turkey Size Oven Bags: The Lightest Option
If you want the absolute lightest pack liner possible, pick up a turkey size oven bag.
One of these bags weighs in at just 0.5 ounces. It isn’t the most durable nor is it the largest — only 19″ x 23.5″ — but reviewers have pointed out that they work well for shorter trips or for carrying fewer items. They’re also multi-use.
5. Lightweight Roll-Top Bags: Heavier & More Expensive, Yet More Durable & Water-Resistant
When your gear must absolutely stay dry, or you’d prefer to buy a more reusable pack liner, consider an ultralight roll-top bag.
These bags are typically heavier — ~2-4 oz — and are more expensive. However they are generally more water-resistant and made out of a more durable material such as Dyneema (fka Cuben Fiber). They’ll withstand tears and punctures better than the above options.
Here are 4 lightweight options designed for ultralight hikers:
- Zpacks Pack Liner Dry Bag — 1.8 oz
- Mountain Laurel Designs Cuben Pack Liners — 2.2-2.5 oz
- Gossamer Gear Pack Liner — 2.5 oz
- Sea to Summit Ultra-Sil Pack Liner — 2.6-4.4 oz
How to Choose the Right Pack Liner for Your Needs
Weight & Durability
Of course, weight is a crucial consideration with any piece of backpacking gear. Lighter is always preferable, but with pack liners — as with most gear — there is a general trade-off between weight and durability.
If you’re going on an overnighter or a shorter trip in good weather, you could get away with a truly ultralight pack liner, such as a 0.5-ounce turkey size oven bag (provided it’s large enough for your gear).
If you’re thru-hiking on the other hand, you’ll likely want something that is larger and somewhat durable (or at least easily replaceable). Trash compactor bags seem to be the go-to budget option, but you could also consider Nylofume and poly bags.
On the heavy side of the spectrum you have roll-top pack liners. These are heavier and pricier but much more tear- and puncture-resistant.
If I were picking out a pack liner I’d try out one of the budget options first, such as a trash compactor bag. If the durability wasn’t to my liking I’d then upgrade to a tougher material.
Dimensions & Capacity
Get a pack liner that is too big for your pack and it adds unnecessary weight and bulk. Get one that is too small and you can’t keep all the gear dry that you wanted.
It pays to know the dimensions of your pack and what gear you want to put in your liner before you buy. That way you have a clear idea of the dimensions and capacity that’ll work best for you.
If you don’t already know, take a moment to find the dimensions of your pack online. Then fill your pack or another bag of known volume with the gear you’ll be putting in your pack liner to get an estimate of how large your liner needs to be.
Since you can always trim down the sides of a bag (if it isn’t a roll-top bag) to remove any unneeded material, I’d recommend erring on the side of buying a liner that is too big rather than too small.
Another way to select a pack liner is based on its reusability.
Are you okay with replacing your pack liner from time to time? Or would you rather buy one ‘for life’?
The plastic bags are more likely to tear or puncture and need replacing, the fabric roll-top bags less so.
Pack Liner vs. Pack Cover: Do You Need Both?
While researching for this article, I saw this question asked all over the place.
Do you need a pack cover if you already have a pack liner, and vice versa? Or do you need both?
After reading dozens of hikers’ opinions I came to understand there is no one-size-fits-all solution to this problem.
First, some hikers worry that the weight savings of not taking a pack cover will be offset by the water weight an uncovered pack might absorb. In the past this might have been true, but modern pack materials absorb very little water. Check to see what material your pack is made out of and whether or not it’s water-resistant.
The second factor at play is your tolerance for having a wet pack. Hikers who are concerned about their pack getting soaked will use a pack liner for the gear they don’t want to get wet and then a pack cover to protect their pack.
For what it’s worth, this strategy appeared to be in the minority. Most hikers seem to use just pack liners.
The final thing to consider is the effectiveness of the pack cover. Multiple hikers reported that pack covers weren’t very effective in heavy rain. A couple people brought up that they can funnel rain down the back of your neck if not cinched down well. They’re also useless if your pack falls in water.
Ultimately, while hikers generally prefer pack liners to pack covers (and to using both), it seems this is a question best answered through trial and error. Buy a cheap pack liner, take it on some backpacking trips, and see if it fully suits your needs. If not, you can always try out a pack cover later on.