Arktis has supplied the British armed forces for decades, but this four-pocket smock works as plain outerwear here: loose, drapey, closer to a field jacket than a shell. The ripstop nylon is woven in a cross-weave that stops a tear from spreading once something snags it, finished with a showerproof DWR. The shape descends from the Denison smock British paratroopers wore in WWII.