The three-button, single-breasted jacket is a classic, but there are some sartorial guidelines to looking confident and fashion-forward.

The key is knowing that, when going from top button to bottom, there is a Button Mantra of Always, Sometimes, Never. That is, on a three-button, the top one is affixed, the second one is or isn’t, depending on preference, and the bottom is never. And since button placements, give or take a centimeter, are always the same, it is perfectly fine to show a glimpse of the dress shirt underneath when buttoned.

I own a hybrid—a blazer with a lapel that transitions from three-button to two-button—but each style is perfectly acceptable and whatever you choose is merely a matter of personal preference.

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