This review is all about a trio of Montane Prisms!
The Prism jacket has been around for a while and is now at version 2. The outer is Pertex microlight and it's filled with 40g of Primaloft. For those of you that don't know Primaloft is best described as artificial down. Weight for weight down will keep you warmer than Primaloft. However, Primaloft doesn't clump when it gets wet unlike down, which then loses most of its insulating properties. Hence Primaloft is usually more suitable for the British climate, where it's more often damp and cold unlike the cold dry weather in an Alpine environment.
So what sort of British conditions is the jacket useful for? It's not really a full on Scottish winter belay jacket, although you could use it under a hard shell. It's more of a three season cold/windy jacket. The Pertex outer is water resistant and will keep out persistent drizzle, but not a full on downpour. However, if it does get completely soaked it dries out quickly. Even in summer it's useful as something to wear at rest stops or at night when camping. My size L only weighs 445g, so it's not too heavy if you are carrying it in your rucsack most of the time. It will pack into its own pocket, taking up very little space in your rucksack.
I am 6ft 2" with a 38" chest. The large size fits me with some room to spare inside and it's long enough to cover my body. I often find that medium sized jackets fit me, but aren't long enough. The Prism has a slight drop tail, so will help stop the small of you back getting cold.
On to the details. The pockets are padded with Primaloft, which makes them good for hand warming. They are positioned fairly high up, so are accessible if you are wearing a waist strap or climbing harness. The cuffs are elasticated keeping out the wind and moisture. There is some soft material inside the zip flap at the head end. This acts as a beard guard and even if you don't have a beard will stop your neck and lips chafing against the material. The full sized hood has a good volume adjuster, which makes it a comfortable fit with or without a helmet. I am not always a fan of hoods, often preferring a hat, but I like this hood.
In use I have found the jacket both warm and very breathable. I have used it for cycling in temperatures between freezing and about 6C over a lightweight Merino top. I didn't overheat or find sweat building up inside the jacket.
I have got a couple of other gilets. A Marmot Driclime, which is excellent for warmer weather and a Paramo Torres. I wear the Torres almost every day at home between Autumn and Summer. It's very and very robust. However, it's not particularly light (???g) and doesn't pack down very small. Thus it's good if you actually wear it all day, but not so good if you are carrying it in your rucksack.
Recently I picked up a Montane Prism gilet. Like the jacket this is filled with Primaloft and the pockets are also Primaloft filled. Also like the jacket it packs away in its own pocket. I can see myself using the gilet a lot from Spring to Autumn worn over a base layer and with my Rab Vapour Rise Lite jacket. Combined with my Montane Lite Speed jacket as an outer layer, these three layers should keep me comfortable in most conditions.
After a long walk carrying a rucksack when I finally set up camp I find that if my legs get cold I end up with bad attacks of cramp. I usually sleep in some thin long johns, to help keep my sleeping bag clean, but if I am just lounging around inside the tent these aren't warm enough.
I have been looking around for something warmer than long johns, that don't weigh much and could also be used to boost my sleeping bag's insulation in winter. Montane's Prism Pants seemed to a good choice. Initially, I had reservations. I have got a pair of Montane Terra trousers, which even in the large size are way too short for my legs. For some reason Montane seem to make their trousers shorter than other manufacturers. However, I needn't have worried as they were long enough. They pack down into a small stuff sack an my size L weigh 318g. There are short zips at the bottom of the legs and a number of press stud fastenings,which let you cinch up the bottoms.
There are no pockets or fly zip. However, for my intended use this isn't a problem. The Rab photon trousers have full length zips, a fly zip, more Primaloft and have pockets. There are also reinforced seat, knees and kick patches. However, they are considerably heavier at 550g for the L size. Most of the additional features are only of use if you intend to wear them all day an while the extra Primaloft makes them warmer, the Prisms should be warm enough for me.