Pack Cover vs. Pack Liner: Which Keeps Your Gear Dry?

Quick Answer

For keeping your gear dry, a pack liner is more reliable and lighter than a pack cover. Use a pack liner as your primary waterproofing and a pack cover only for extra protection or when you need to keep the pack fabric dry.

Rain can turn a good hike into a soggy mess, especially when your gear gets wet. Two common solutions are pack covers and pack liners. Both aim to keep your backpack contents dry, but they work differently and suit different needs.

In this comparison, we break down the trade-offs between pack covers and pack liners, using real product examples from Six Moon Designs to help you decide which is right for your next trip.

How Pack Covers Work

A pack cover is a waterproof shell that fits over the outside of your backpack. It shields the entire pack from rain, snow, and splashes. This keeps the pack fabric dry and can protect less waterproof items in outer pockets. However, pack covers add weight and bulk, and they can snag on branches or flap in wind.

Pack covers are most useful in steady rain when you want to keep the pack itself dry. They are also handy for protecting gear in external pockets that are not waterproof. But if you are trying to save weight, a pack cover may not be the most efficient choice.

• Consider a pack cover if you often hike in sustained rain and want to keep the pack fabric dry.

How Pack Liners Work

A pack liner is a waterproof bag that goes inside your backpack. You place your gear inside the liner, roll the top closed, and then pack it into your backpack. This method keeps your gear dry even if the pack gets soaked. Pack liners are typically lighter and more compact than pack covers.

The main trade-off is that the pack itself gets wet, and you need to organize your gear to fit inside the liner. But for ultralight hikers, a pack liner is often the preferred choice because it offers reliable waterproofing at a minimal weight penalty.

• Use a pack liner to protect your sleeping bag and clothes from water even during river crossings.

Comparing Weight and Reliability

Pack liners are usually lighter than pack covers. For example, a 50-liter pack liner from Six Moon Designs weighs about 3 ounces, while a pack cover for a similar pack might weigh 5 to 8 ounces. The weight difference matters for long-distance hikers who count every gram.

In terms of reliability, pack liners are more foolproof because they protect your gear from water that can seep through the pack fabric or zippers. Pack covers can fail if they are not securely fitted or if water runs between the cover and the pack. However, pack covers keep the pack itself dry, which can extend the life of your backpack.

• Weigh your options: if you prioritize weight and guaranteed dry gear, a pack liner is the better bet.

Trade-Offs at a Glance

• Weight: Pack liners are lighter (e.g., 3 oz for a 50L liner) than most pack covers. If you're counting grams, a liner is the leaner choice. Choose a liner for ultralight setups.
• Protection: A cover keeps the pack fabric dry but can fail if not fitted well. A liner keeps your gear dry even if the pack is soaked. For guaranteed dry gear, trust a liner.
• Convenience: A cover is quick to put on and take off. A liner requires packing your gear inside it each time, which takes a bit more effort. If you value speed, a cover is more convenient.

Product Facts

• Pack Liner: Designed to fit inside of your pack, our Pack Liners help protect your gear from the outside elements. The pack liner is a 50 L or 75L, roll-top bag, made with waterproof material and taped seams to keep your pack's contents dry. This liner offers reliable waterproofing from the inside, making it ideal for keeping your gear dry even if your pack gets soaked.
• Flex PR Plus Pack Rafting Backpack: The Flex PR+ is a multi-use pack specifically designed for pack rafters. The Flex PR is a 75L dry bag with a removable suspension system designed for carrying heavy loads in comfort. This pack is essentially a built-in dry bag, so it provides waterproofing without needing a separate liner—great for pack rafting and canoe trips.

Which Should You Choose?

Best for

• Ultralight hikers who want minimal weight and reliable waterproofing—use a pack liner.
• Pack rafters or canoeists who need dry gear even if the pack goes in the water—consider a dry-bag style pack like the Flex PR+.

Not for

• Hikers who want to keep the pack fabric dry and prefer quick on/off protection—a pack cover might be better.
• Those who need to access gear frequently during rain—a liner can be less convenient than a cover.

Both pack covers and pack liners have their place. For most backpackers, a pack liner offers the best balance of weight, reliability, and simplicity. Use a pack cover if you want to protect the pack itself or prefer the convenience of external protection. Either way, keeping your gear dry is the goal, and both methods can help you achieve it.