A good suit deserves a good fabric: a great suit deserves a fine fabric...or maybe even a coarse one. It depends. Confused? You won't be, after you read this little tip sheet on S numbers.
Choosing the S Number for Your Suit
What is an S Number?
An S number or Super number is a fabric-industry standard for measuring the fineness or thickness of a wool thread made into a fabric (S numbers are used to describe threads that are at least 45% wool). It's a little like thread count in sheets. The higher the S number, the finer the yarn and the lighter weight and drapier the fabric can be made. This will affect the way your suit hangs, the sheen on the surface, its weight, and to a degree even the embellishment and detailing it can take.
S numbers have even become something of a status symbol lately thanks to aggressive marketing, although we really feel that there is a place for thicker fibres as well as thinner ones. It's just a matter of choosing the right fibre for the suit, the use, and the wearer.
It might seem simple to conclude that higher S numbers, ie finer fabrics, are what you want for a good suit, but in fact that's not the case. The use and style of the suit will dictate what kind of fabric, and what S number, is appropriate.
Pick a Suit Fabric for the Occasion
Think of a great, tweedy suit, ready to go grouse-hunting at a moment's notice (or at least look like it while you stroll the Seawall). A silky, high S number fabric would be the wrong choice for something so outdoorsy; that kind of suit demands a thicker fibre, something more rugged than, say, you would want for your dinner jacket.
Lower S number fabrics are also more resistant to wrinkling than high S number fabrics, and more durable. They are less glossy, but as with tweed, a good fabric design takes advantage of this textural difference, rather than hiding it.
High S number fabrics are suitable for more formal, indoorsy and sophisticated ensembles. Think of a wedding suit, a dinner jacket, or the perfect blue suit on the jet-set scion of a Dubai banking fortune. Not necessarily a look for every day! And the fineness of the fibre adds to the cost; you will be paying substantially more by the meter for high S number fabric than for lower. For a special occasion, there's no beating a high S number for impact and sophistication.
Anything from Super 100 and up is technically considered "fine" in all senses of the word. Between 100 and 120 is a good range for an every day, hard wearing suit that will stand up to travel and frequent wearings. Once you get to the 150, 160 range, you're talking about a special occasion fabric for a special occasion outfit. You're also talking about something that's much more difficult to sew, which is why you and your tailor need to be on the same page from the beginning. More communication is better.
Talk to Your Local Tailor
Rather than focusing on the number, talk to your tailor and get an understanding of which fabric is best for the use you have in mind. You wouldn't wear jeans made out of chiffon, nor would you wear pyjamas made out of burlap. Your tailor is an expert, and will guide you to fabric options which are both practical and attractive.