I’m never going to advocate leaving your waterproof jacket at home when heading into the hills, but if you’re pretty sure it’s going to spend most of the day in your rucksack there’s no need for a heavy winter-spec mountain waterproof. Thankfully modern designs and outdoor fabrics have led to some very well-featured lightweight jackets that add little to your packweight but may not have the durability and breathability of heavier fabrics. The breathability of waterproofs is a source of major consternation and pub arguments, so rather than writing an essay on unrealistic consumer expectations and the joy of windshirts, this article…