From the age of 6 I was brought up in a Mountain School in the Lake District, where my father worked for 30 years. For 25 of those years he was a member of the Mountain Rescue, prior to this he's been in the army reserves. He had seen the best and worst of what UK & European mountain weather could bring - from Sca Fell to Mont Blanc. In all that time, having used almost all types of mountain clothing, he only ever raved about two pieces of kit (and I mean really raved about them) and the one he went on about the most was the Buffalo Mountain Shirt.
The first thing you need to know about this piece of kit, so beloved of Climbers, Mountaineers and HM Special Forces is that it's not a shirt, it's what we'd call a "smock". It's suitable for most winter conditions and thanks to the way it works is ideal for UK walking and climbing from October to March. Out of this time it's going to be too hot to wear. It's not bulky, it weighs about the same as a heavy Gortex waterproof and the technology it uses is not developed in a corporate lab, it's borrowed from the Inuits.
Buffalo was founded by mountaineer Hamish Hamilton in the late 1970s after he had been disappointed with the performance of the mountain equipment and clothing he had been using in the Scottish Highlands. There is something very British about his invention of Pertex, the fabric he developed in conjunction with Perseverance Mills in Padiham, Lancashire. One of the stories involves him staring at the way ink moved across the fabric of a typewriter ribbon - the distribution of moisture was key to the success of this material.
The Mountain Shirt works best when it is worn next to bare skin - the Double P System developed by Buffalo repels moisture from the outside, whilst eliminating it on the inside, wicking moisture away from the wearer to the outer shell where it is dispersed and quickly evaporates.
Wearing one layer can feel very weird when you are used to lots and lots of layers, but you soon get used to it and realise it will not betray the trust you have bestowed upon it. If anything, once moving you will be too warm, but you can regulate your heat extremely effectively with a series of zips.
It's the most imitated item Buffalo have ever produced, but it's never really been equalled - they are not interested in being this season's "must have", the shirt has not changed much since it's initial design.
There are lots of stories on Buffalo's website from people who have worn the shirt and found themselves in a spot of bother on a freezing mountain. My favourite ones concern people wearing Buffalo clothing who have fallen into freezing water, got up and (after moving around) suffered no real adverse effects - in fact after 20 minutes they have been nearly dry.
When I think about the money I see wasted on expensive Goretex "big name" jackets that are depressingly not up to the job, I can't help but love my Mountain Shirt. This simple item costs around £100, is only ever manufactured in Sheffield and has been confidently doing the business for serious mountain people for over 30 years.