The blazer has outlasted every fashion trend of the past 160 years. Not because it carries some vague timeless quality — but because nothing else in a wardrobe does its specific job. It elevates a plain T-shirt. It makes denim boardroom-adjacent. It works equally hard at a wedding, a job interview, and a Friday dinner out. Most blazers people own are the wrong ones. Too fused to hold shape past 18 months. Wrong shoulder. Wrong for the occasions they were bought for. Here is what actually separates a great blazer from a structured piece of fabric you’ll stop reaching for.…