The trench coat, piece by piece

Every detail on a trench coat started as an answer to a problem, and most of the problems were rain. Taking the coat apart explains why it looks the way it does.

The cloth: gabardine

Gabardine is a densely woven cotton, invented by Thomas Burberry in 1879 and patented in 1888, according to Burberry’s own company history. Its trick is the weave: a high thread count in a compact twill, with small pockets of air that let vapor out while blocking wind and water — a genuine improvement over the heavy, stiff waxed and rubberised rainwear of the era. It is not waterproof in the modern technical sense: a trench keeps you dry in a shower and loses in a downpour.

The parts, and what they do

The details that survived are the military ones. During the First World War, Burberry developed the trench for officers, and its history page describes each addition plainly: the epaulettes displayed insignia, the gun flap gave additional protection, the D-rings were used to attach military equipment, and the storm shield allowed rain to run off more efficiently. More than 500,000 Burberry coats were worn by the armed forces. On a modern trench:

• Storm shield (storm flap): the panel over the chest and shoulder, keeping rain from running straight down the buttoned front.
• Epaulettes: shoulder tabs. Rank, once; a silhouette cue, now.
• D-rings and belt: the rings originally clipped kit; the belt still does real work — it gives the coat its shape when open.
• Gun flap: the buttoned panel over one shoulder, a second layer where a rifle strap would have sat.
• Deep pockets and cuff straps: maps, once; gloves, now.

The cotton catch

Cotton gabardine creases. That is the trade for breathability, and no marketing removes it — a trench is meant to look lived-in rather than pressed. What you can choose is the weight: a lighter gabardine drapes and packs better and weathers faster; a heavier one resists wind and holds the collar’s shape for years. Heritage versions are woven at a single mill and sewn with structured collars that take a skilled hand to assemble — the real reason for the price gap.

Sizing: bigger, not smaller

A trench is a layering garment. The classic cut assumes a suit or a thick knit underneath, so the armholes are generous by design. If you are between sizes, take the larger one — a tight armhole is the one fault no tailor can fully correct. Two checks matter more than the size label: the shoulder seam should sit at your shoulder point, and the sleeve should reach the wrist bone with the arm slightly bent. Length matters less than people fear; the traditional proportion ends mid-thigh, longer skews formal.

Care

Most cotton trenches are dry clean only — the label is the authority here. Between cleanings, a clothes brush and airing handle most of it. Store it on a broad hanger, and do not squash it behind a season of other coats. If the cloth stops beading water as reliably, it has been cleaned or worn thin — there is no home re-proofing for gabardine the way there is for waxed cotton.

How to choose

Fit the shoulder first, size for layers second, length third. The details that matter are the storm shield and a real belt; buy the cloth weight for your climate.

The trench has not changed in a century because it worked the first time.