Thursday, June 7, 2007

What Does Super Wool Mean?

Why the numerical designations-Super 100s, Super 120s, Super 180s-for ultra-lightweight wools don't mean what you think they do. The thread of this story is the numbering system used to describe the new breed of super-lightweight, high-twist wools. Pioneered by Italian mills about ten years ago, these fabrics are made using high-tech machines that spin wool lighter and finer than it's ever been spun before. The various grades of cloth are referred to as Super 100s, Super 120s, Super 150s and so on, up to Super 200s, which Oxxford Clothes started using last year for a line of suits. (As far as I know, this is the top of the super-lightweight wool pyramid right now.) The problem is the impression left by the numbering system. Set up as a shorthand for describing the fineness of wool fibers, it has, in the process of trickling out into the marketplace, come to be taken as a quality ranking. It's easy to assume a Super 120s wool must be better than a Super 100s wool and not as good as a Super 150s wool-in short, the higher the S-number, the better the fabric. That's simply not true, and no less an authority than Paolo Zegna, the textiles division president of Ermenegildo Zegna, describes the S-system, as it's known in the trade, as "a very big confusion." Zegna doesn't use S-numbers at all, preferring to describe its lightweight wools as High Performance or 15 Milmil 15, for example. Still, the S-numbers persist, a lingua franca that's irresistible because it reduces a complex subject to a sort of yardstick. The S-system dates back to the 18th century (also known at the time as the worsted count system), and then as now it denoted the fineness of a given bale of wool. In those days finished yarn was coiled into 560-yard-long loops called hanks. The S-number indicated how many hanks could be gotten out of a pound of wool. The finer the wool yarn, the farther it would go. The S-scale ran from 30s to 100s, then the finest wool available. (Today 100s wool is practically the bottom rung of the S-scale.) The S-scale remains even though hanks are long gone. Now the number refers to the fineness of the wool as measured in microns (one-millionth of a meter). Does that mean finer is better? Not necessarily. As Paolo Zegna explains, "You can have a good 15-micron wool or a bad 15-micron wool." (Finer does mean more expensive: Oxxford's suits made from Super 200s wool retail for $14,000.) Fineness is just one quality component: Length, strength, color, and crimp are also important, with the first two particularly so. Length is critical because the longer the fiber, the stronger the yarn that can be spun from it. Strength is critical because the yarn must be twisted very tightly (hence the name high-twist fabric) to achieve a fine weave. The way in which the fabric is finished also plays an enormous role in the feel and look. At Dormeuil, I have seen Super 100s wool that felt as sumptuous as Super 120s or 140s because of the finishing.

No comments: