A jacket can have many virtues. Sharp elegance or easy charm. A flattering silhouette. Protection from the weather. Somewhere to keep your phone. A good field jacket has them all.

Like so many classic designs, the contemporary field jacket is military in origin. It’s a direct descendant of the U.S. Army M-65, and further back, safari jackets, and other warm-weather uniforms. This combination of adventure and discipline helps to explain why the garment excels in both casual and formal civilian contexts.

Trunk’s own model, the Blandford, was designed to capitalise on this versatility. It’s light enough to wear from a wet spring through a hot summer and into autumn, and long enough to sit comfortably over a suit jacket as well as over a t-shirt. It combines the best features of an overshirt and an overcoat. This season it’s been simplified and streamlined to give this supremely practical garment an even sharper finish.

Key to the Blandford is the fabric: crisp cotton sourced from Japanese cotton specialist Shibaya in Osaka. The dense weave makes it sturdy and showerproof in spite of its fineness. And thanks to its lightweight nature, you can easily roll and pack it on any trip where the weather could take a turn for the worse.

Most jackets provide storage space as well as protection from the elements, but the field jacket is unrivalled as a packhorse. The four outer pockets are easy to access, ideal for outdoor pursuits. The waist pockets have a subtle bellows construction, meaning they can be loaded up when necessary, as well as side entry for easy access on the go. On the inside, another four pockets are perfect for tickets and documents when travelling.

In terms of style, too, the Blandford is a jacket for all occasions. Like a sports jacket, its length complements the higher waist of a tailored trouser. Its structured collar can be worn raised, giving a touch of raffish charm, and a drawstring waist provides a touch of extra shape. Thanks to its classic styling and fabric, it wears like classic outerwear rather than contemporary waterproof gear. At the same time, it’s unstructured through the body and generous in fit, meaning it relaxes into the most casual of outfits and can easily be layered over a structured jacket or knitwear.

For an easy casual look, layer it over a classic tee and pair it with jeans and sneakers, or wear it with cotton chinos and suede chukkas for an elevated off-duty alternative. For a smarter option, try it in place of a heavier, full-length raincoat in a formal outfit. The navy model is a natural match for grey suits of every shade from charcoal to dove, and the ideal partner to high-twist, tropical wools, at home and on the road.