Women's Single-Breasted Blazer

Buttons run in a single column and the front closes almost edge to edge. This is all single-breasted means, and it explains why this jacket looks deliberate whether you fasten it or leave it hanging open. A notch lapel, the common shape with a step cut where the collar meets the lapel, sits on nearly all of them. Buttons come in ones, twos and threes, and the count changes the outfit more than the color does.

A single button sits lowest and opens the front into a long V, which lengthens the torso and shows more of what is underneath. Two buttons close higher, cover more and make the safest first jacket. Three shortens the visible torso and reads either formal or retro depending on the cloth. Only the top button fastens on a two-button jacket, since the pattern is cut expecting the lower one to stay open. Forcing it shut pulls the hem apart at the vent.

A Double-Breasted Blazer wraps its front across itself and has to stay buttoned to hold shape. Volume separates it from an Oversized Blazer, which keeps this front and pushes the shoulder seam well past your arm. Cropped Jackets end the hem above the waist and lose the hip pockets with it. Outerwear treats a blazer as a light layer for dry weather; judged here as tailoring, it stands or falls on canvas, armhole and shoulder rather than on warmth.

Business casual is where it does the most work, in rooms where a knit reads as underdressed and a full suit looks like a job interview in progress. Navy, black and a mid gray each carry jeans, Tailored Trousers and a Slip Dress equally well. Cloth sets how formal it looks. Worsted wool with a faint sheen reads formal, while flannel, tweed, linen and cotton relax it enough for denim. Buying only one jacket, take an unmatched cloth, since a suit jacket worn alone looks orphaned.

Buy the shoulder and alter the rest, because letting a waist in or shortening a sleeve is routine work while moving a shoulder costs several times as much. Fold a lapel over your finger and let it go, since a canvassed front pushes itself back into shape while a glued one keeps the crease. Choose two side vents over a single center vent if you keep your hands in your pockets, since one vent gapes open the moment you do. Rest it a day between wears and brush it downward before it goes back on the rail.