Sleeping Bag Liners
A sleeping bag liner is one of the most versatile additions to any tramping kit. It adds warmth, maintains hygiene, and can extend the useful range of your sleeping bag across seasons. Lightweight and compact, a liner earns its place on any multi-day trip.
At Dwights, we stock the Peak XV 100% Silk Sleeping Bag Liner and Cocoon liners — both practical options for NZ tramping.
What a Liner Does
- Adds warmth: A liner adds 3–8°C of effective warmth to your sleeping bag, depending on material. Silk adds the least; fleece and thermolite add the most. Adding a liner to a -3°C bag can push its effective rating to -8°C or colder.
- Maintains hygiene: Body oils, sweat, and dirt accumulate in your sleeping bag over time — washing a full down bag infrequently is preferable to preserve the down. A liner sits against your skin and can be washed regularly, keeping the bag clean longer.
- Extends versatility: A liner in summer (or in a warm hut) can be used alone. The same liner in winter boosts your bag's warmth. One piece of kit, two use cases.
Liner Materials
- Silk: Lightest and most packable. Soft against skin, naturally temperature-regulating. Adds 2–4°C. The Peak XV Silk Liner is our core recommendation for tramping.
- Cotton: Comfortable but heavy and slow-drying. Better for car camping than tramping.
- Thermolite/synthetic: More warmth than silk, still packable. Adds 5–8°C. Better for cold-weather use.
- Fleece: Maximum warmth addition. Heavier and bulkier. Suited to cold base camp use.
Frequently Asked Questions
Are sleeping bag liners worth it for NZ tramping?
Yes — particularly for multi-day Great Walk tramping where you're sleeping in DOC huts with varying temperatures. A silk liner adds meaningful warmth at minimal weight (typically 90–130g), keeps your sleeping bag clean across a week-long trip, and can double as a standalone layer in warm huts. The weight-to-benefit ratio is excellent. If you're doing the Routeburn in shoulder season and want to extend the warmth of a lighter bag, a liner is an efficient solution.
How much warmth does a sleeping bag liner add?
Silk liners add approximately 2–4°C; thermolite synthetic liners add 5–8°C; fleece liners add 8–10°C. The actual warmth addition depends on the liner material, construction, and how well it fits inside your sleeping bag. A well-fitting liner that sits flush against your body transfers warmth more effectively than one with excess material bunching inside the bag. As a practical guide: adding a silk liner to a -3°C bag gives you effective coverage down to approximately -6°C to -7°C.
Can I use a sleeping bag liner on its own?
Yes — in warm hut conditions (summer Great Walk huts can be genuinely warm) a silk liner alone is sufficient and significantly more comfortable than being inside a full sleeping bag. Most trampers use the liner inside their bag in colder conditions and on its own in warm huts. It's one of the few items that genuinely earns its weight twice.