The field shirt is an unstructured shirt or structured jacket, depending on where you draw the line. It is, either way, your quintessential mid-layer. It is suitable over a shirt or t-shirt — with a capacious cut in the upper body — but is unlined and bulk-free, so can be sandwiched between your shirt and jacket.
The collar of the field shirt sits atop a full collar-stand, which itself has grown onto it a short throat tab. The tab is probably happiest undone — it isn't so long that it ever mopes around aimlessly — but can be whipped across to the opposite side to keep out the wind, or buttoned back on itself, out of sight.
The buttons are horn, and are dark in colour and matte in finish. Being as they're only a step or two from nature, each one is different, in terms of shade and marking. Those at the front are attached through eyelets and a metal ring — "butcher's buttons", sometimes they are called — and are thus removable.
There are two pockets on the field shirt, both at the chest. They are built into the chest-spanning seam that stems, in point of pattern-cutting fact, from the sleeve. One is a bellows patch; the other is an in-seam pocket, the stitching for which mirrors its counterpart. Bar-tacks strengthen the entranceways of both.
There's no arm or shoulder seam on the field shirt. No raglan, no in-set, no nothing. The absence of seam in the region means that the field shirt has the softest imaginable shoulder: for better or worse, it rolls over the outline of the wearer.
Strong little tacks abound on the smock, strengthening points expected to endure the most stress. The mouth of the pockets, for instance, or the pleat at the back yoke.
The cuffs are unusually squat: more coat-like in styling than shirt. They fasten with the help of an arrow-tipped tab and button. The relatively wide sleeve is pulled into this cuff with the the force of a gusset and the grace of a pleat — although the cuff is quite wide so the shirt is easily slipped off and on.
Linen of real character, this, rich with slub and bobble. While exceptionally heavy, it is also breathable, and held up to light can be seen to have a gauze-like airiness to its structure. It is a washed, so out goes the natural starchiness, and in comes a soft and comfortable handle.