This lightweight mid-layer packs small and is well-suited to backpacking, says Chris Townsend.

Mountain Equipment’s Particle jacket is designed as a “mid-layer or outer layer for use in moderate conditions”. It’s lightweight and packs small, making it ideal for backpacking or carrying in the pack for rest stops. The main shell fabric is windproof, but the fleece side and underarm panels aren’t. The stretch fleece panels mean the Particle can be close-fitting without restricting movement. The Medium fits me over a thin base layer but would be tight over a fleece. But then this is really a warm alternative to a fleece.

The design is basic and more suited to a mid than an outer layer. There’s a simple snug-fitting hood that does blow back a little in strong winds as it’s non-adjustable. The handwarmer pockets are cut off by a hipbelt. There are no other pockets. 

The Mountain Equipment Particle isn’t a full-weight winter jacket for the coldest conditions, but as a winter mid-layer under a shell jacket it should be fine and it’s great for backpacking the rest of the year. The test jacket didn’t arrive until early summer, so I’ve only used it on cool mornings and evenings when it’s been fine in camp and for gentle strolls.

See how Mountain Equipment’s Particle compares to other synthetic jackets in our guide to The best synthetic insulated jackets