Why Only Button the Top Button?
Admittedly, it’s an odd standard. Why have a button that’s never supposed to be buttoned in the first place? Finding the answer requires a brief dive into history.
Edward VII was the King of the United Kingdom between 1901 and 1911, a timeline that coincides with the introduction of “the lounge suit,” the precursor to the modern business suit. The King was on the stouter side, and as a result he always left the bottom button of his suit jackets undone. His courtiers began to imitate it, and soon the trend was set.
Men today don’t need to consider a monarch’s personal style when getting dressed, but gradually jackets were designed with the idea that only the top button (or for a three-button jacket, the top and middle) would be buttoned. As a result, buttoning that bottom button may cause the jacket to appear tight around the hips, making the wearer look heavier as a result. It also diminishes the inverted “V” that forms at the bottom of the jacket when the top button is buttoned, throwing it out of harmony with the upright “V” above it.
If there’s ever an exception to the rule, it’s if you happen to be outdoors in the freezing cold without another layer of clothing. However, a warm topcoat can take care of that problem much more effectively.