Tested: Montane Prism Sleeping Bag

I’ve been looking for a lightweight, highly packable three-season sleeping bag for a while now. Paired with a NeoAir XLite sleeping pad, it would give me almost year-round protection and comfort in a package that was still small enough to throw in my hand luggage. Hand luggage? Sure, you never know when you’re going to appreciate some emergency shelter, and a decent sleeping bag and mat can make all the difference between a tolerable travel delay and something that leaves you exhausted and jet-lagged for days.

I initially wanted a down-filled bag because down gives you the best insulation for the smallest possible packing size. Yet, when I thought it through, I couldn’t be completely sure that I’d be able to keep the bag dry, and down is all but useless when it’s wet; it clumps and refuses to loft, so there’s no space for warm air to be trapped. Trying to sleep in a damp down sleeping bag is like trying to sleep under a couple of sheets.

So, I started looking elsewhere. Montane’s Primaloft synthetic insulation had impressed me before – and I’m a huge fan of Montane clothing – so it seemed a fair bet that a Primaloft-filled sleeping bag would be a decent compromise between all-weather insulation and a small-ish pack size. The Montane Prism sleeping bag weighs 1.248kgs and comes with a loose-fitting storage bag as well as a compressible dry-bag for use when you are travelling.

With a breathable and water-restant PERTEX outer and 160g of PRIMALOFT SILVER ECO filling (containing 70% recycled content, no less) it has an independently certified comfort rating of 0ºC, so it should suit European and North African camping almost all-year-round, especially as its extreme rating – with proper insulating clothing and a bit of discomfort – is minus 16ºC. (I’ve got a Alpkit ArcticDream 1400 down-filled bag for seriously cold weather.)

First impressions are good. At 1.94m it’s just long enough  to accomodate my 6′ 3″ frame and broad enough to squeeze in while wearing some winter clothing, too. The ‘flipper foot’ design is very close-fitting, which isn’t to my taste but is designed to keep your feet toasty without having too much wasted space to heat needlessly. The neck has a decent baffled collar to keep the warmth in, the hood fits snugly around my head, and the synthetic filling feels surprisingly down-like in texture and packability.

The underside has silicon dimples to grip the sleeping pad, and there are a couple of inside pockets for a phone, keys and wallet. The zip opens from the top and bottom, so you can ease it open a few inches at the foot end if you get too warm, or undo it all the way and use it almost like a duvet.

On the downside, the PEAQ synthetic inner lining is a bit too shiny and feels cold to the touch, but it is said to be breathable. Still, on balance, I’d rather have had more of a cotton-like liner.

The Prism sleeping bag comes with Montane’s lifetime warranty and, best of all, can be found for as little as £100 without too much searching. At that price it’s an absolute bargain.

 

Carlton Boyce @motoringjourno