Even in today's world of mass production, there's a lot that goes into constructing a good button-up shirt. Construction details like stitch types, plackets, darts, yokes, collar styles, and a whole lot more determine what sets one garment apart from another, so you end up with a stunning amount of potential variation. Where it all begins, though, is the shirt's fabric.
Threads
Apart from the type of weave, there are two main aspects of a shirt's fabric: the thread count (aka yarn number) and the ply.
Thread Count
This is a measurement of yarn size and density, ranging from 24 up to the 200s. A higher count is usually more expensive, since the extra thin yarns used can only come from the most highly prized cotton fibers. But that's not to say it's always your best bet.
High thread count shirts wrinkle easily and tend to be very lightweight, though you do get an extra soft and smooth texture. And for certain weaves like oxford cloth, a low thread count is your only option since the thicker yarns are necessary for the specific look and feel.
Ply
This is the number of strands on each yarn. Single-ply means that there's just one strand, while two-ply means that each yarn has two strands twisted together. Two-ply is preferable since it's more durable and makes for higher quality fabric, though there are two different types.
2x2 means that both the horizontal and vertical threads are two-ply, while 2x1 means that only one of them is. And at the bottom of the barrel, 1x1 means the fabric is single-ply in both directions.
Weaves
Fabric images courtesy of Proper Cloth
All shirting fabrics use some combination of horizontal and vertical threads. Where it gets tricky, though, is in what order they're woven together. Here are the ones you're most likely to come across:
Broadcloth
A tightly woven plain weave -- meaning the horizontal thread goes over a vertical thread, then under the next, then over the next, and so on -- which, back in the day was woven 72 inches wide instead of the standard 36. The density of the yarns gives it a subtle shine and low texture, which tends to look a bit formal, so you'll usually find it used for office-ready dress shirts.
It's relatively thin and light, though, which is nice for the summer but can make white shirts slightly transparent. Oh, and for all intents and purposes, it's interchangeable with poplin, which can sometimes have vertical and horizontal yarns of different weight but is otherwise identical.
Chambray
Like broadcloth, this stuff uses a plain weave and is fairly light. But unlike broadcloth, it uses slightly heavier yarns with a colored vertical thread and a white horizontal one, and gets a unique sheen from a finishing process where it's folded and pressed through rollers at a high temp and pressure, called "calendering."
It was originally made in Cambria, France (hence the name), has a firmly casual vibe, and most commonly uses blue vertical yarns -- which, combined with the white horizontal ones, is easy to mistake for denim. Without the calendering, it would be end-on-end.
End-on-End
This is nearly identical to chambray, except that it doesn't share that fabric's subtle shine from the calendering process.
End on end uses the same plain weave with a white horizontal thread, so that it looks solid from a distance, but up close you can see the white threads shining through. And like chambray, it's typically light and good for warmer months.
Oxford
A heavy, durable, versatile fabric that gets its unique feel from a basketweave pattern.
It was first made back in the 19th century by a Scottish mill along with Yale, Cambridge, and Harvard cloths (what, you mean your university doesn't have it's own shirting fabric?), though those others have since gone extinct. It's a slightly preppy wardrobe staple that looks perfect with a few wrinkles and a pair of jeans.
Pinpoint
A tie-ready take on oxford cloth. It shares the same pattern, but uses a finer yarn and a tighter weave so that the finished product feels softer and smoother -- though relative to other fabrics besides oxford cloth, it's still fairly heavy duty.
It toes the line between casual and formal, so you can dress shirts made out of the stuff either up or down, though it's not quite as boardroom-ready as some other options.
Twill
If you look closely at this stuff, you'll see (and feel) some very subtle diagonal ribs. That's because each row of the horizontal threads' weaving over and under the vertical ones is offset from the row before it -- so the "over" sections make a diagonal line.
The yarns are especially dense and fine, making for a super soft fabric that drapes particularly well. It's a strong choice for dress shirts, especially because it's fairly wrinkle resistant.
The right combination of thread count, ply, and weave depends on personal preference and how you plan to wear it, so there's no one fabric that'll work for everyone. But knowing the differences between all your options lets you shop smart when it's time to add a new shirt to your wardrobe.
