The least formal but still correct dinner jacket that a man can own is the double breasted shawl collar. Colored black, midnight blue or even dark brown like the one Noel Coward wore with matching brown trousers, the shawl DB is one small step up from a smoking jacket, and two big steps down from white tie and tails. That is because the shawl comes directly from the smoking, which took it from the dressing gown. And the DB jacket evolved from the single breasted coat, which was in turn descended from the single breasted tailcoat.
The double breasted DJ was trailblazed by the late Duke of Windsor and his set when he was Prince of Wales. Its closed front means a man needs not bother with waistcoat and cummerbund. The man who wears one with a soft shirt with turndown collar is as close as he can publicly come to the clothes he would have worn at home years ago, when the men had retired for brandy and cigars.
Photo: James & James for the Men's Fashion Council