In certain sub-sects of menswear enthusiasts, there is a serious fetish for an extremely fine type of suit wool with an extraordinarily soft hand. These wools are delineated by what is called an “S” or “Super” number. The higher the S number, the finer the wool.
The number itself refers to the number of times the wool thread is twisted. The more the yarn is twisted, the finer and thinner it gets, yielding a super-soft fabric with an extremely silky feel.
The average wool suit that most men wear is probably made with somewhere between a Super 100s and a Super 120s. Maybe up to a Super 130s on the outside. The ultra soft (and ultra expensive) wools happen at around a Super 150s and can flirt with 200 or higher.
Here’s the thing with the higher numbers, though: While these high Supers are extraordinarily soft, they’re also very delicate, making them very impractical for regular wear. Sit for an hour in a suit made with Super 180s wool, and you’ll be far more wrinkled than someone wearing a Super 110s. Another drawback is that the high Super wools don’t “bounce back” like the lower numbers, which means your suit will need a press or a steam before each wearing.