It’s a term that comes up often when buying shirts and suits, but what does yarn count mean? Our brief guide delves into the construction of fabric to assess how ply and yarn count mark its quality.
Dress yarns can be either single-ply or two-ply. A good quality shirt is woven with two-ply thread which consists of two pieces of thread twisted together to make a ‘single thread’. Single-ply consists of one twisted thread. Two-ply fabrics are superior to single-ply as they generally have a tighter weave, ensuring greater durability, longevity and a stronger and softer shirt.
Yarn count (or thread count) is the number of threads per square inch within a fabric. What affects the yarn count is how thin or thick the yarn is – fibres that are larger in diameter will have a smaller yarn count as fewer of them will fill in a square inch. Conversely, fibers that are thinner in diameter will have a larger yarn count.
Woven fabrics have two sets of yarns run through it. The thread that runs vertically through the fabric is the warp and the thread that runs horizontally through it is the weft. Fabrics with a low yarn count are more loosely woven. Fabrics with a high yarn count are more tightly woven
Yarn or thread count is referred to in numbers such as 50s, 80s, 100s, 120s, 140s 160s, 180s and 200s. A yarn count above 100 usually implies that the fabric is two-ply. Fabrics with a low yarn count are generally weightier fabrics of greater durability. Fabrics with a higher yarn count are composed of finer threads which results in a softer, smoother, lighter fabric with greater drape. The general idea is that the higher the yarn count of a shirt, the better quality the shirt is. A dress shirt can range between a count of 100s to 200s. Within this, the optimum count for a high-quality shirt lies between 120s and 140s.
As thread count increases, the diameter or thickness of individual fibres decreases. The diameter of the individual thread is measured in microns. The yarn count of a suit is counted in ‘super numbers’ which factors in the threads per inch (the fineness of the wool) with its micron number. The general standard is that a quality fibre has a diameter lower than 19 microns but greater than 15.5 microns while a fine quality fabric has a yarn count of Super 100 or higher.
Suits that range from super 70s to 90s are created from a heavyweight and extremely durable wool that promises to keep its wearer warm. Suits made from a super 100s to 120s grade wool are still durable but are thinner, lighter, more comfortable and tend to work for most settings. For a suit more suitable for warmer weather, fabrics in the super 130s to 140s count result in more fragile suits but with a finer, softer and lighter feel. At its highest-end, some rare luxury wool suits and tuxedos are composed of a super 150s to 200s count, creating a delicate finish reminiscent of silk in texture and weight.
Above this, it is possible to reach a point of fineness which yields diminishing returns. A yarn count above 200 would be expected to be woven with fibres so thin (and fragile) that they weaken the overall structure of the fabric. In the same way, fibres that are less than 15.5 microns in diameter can be fragile and prone to breakage.
When choosing a fabric, it’s important to clarify your requirements with the fabric’s parameters. How will it function with accordance to the purpose and frequency which it will be worn? Once happy with the yarn count, it’s important to factor in the production process: a high-quality yarn count will only live up to its reputation if the yarn it is composed of is of equally high quality.
Test it out
A good way to test the yarn count of your fabric is to hold it up against a light source – the less light that shines through the fabric proves a higher thread count.