To understand the fabric we have to firstly understand the yarn and the nature of fibres. Natural fibres are always the preferred choice, wool, cotton, linen, silk or even bamboo!
They are all absorbent and therefore they take colour well but also absorb perspiration and in themselves carry a natural insulation against heat and cold.
The thickness of fibres are measured in microns which is a diameter of the fibre. The finest merino wools are 10 microns (very rare) with the thickest 25 microns, but the average is between 12 and 15 microns. In 2008 a bale of 11.6 micron wool was produced by Hilcreston Pine Hill Partnership in Australia and sold for just under $1.4 million dollars.
In 2010 10 micron fleece Windradeen New South Wales won the Ermenegildo Zegna Vellus Aureum trophy for the finest and softest fleece that year.
The terms 100’s, 120’s, 150’s refers to the fineness of the yarn spun from the wool fibre. Some yarns are single ply, where one fibre is spun into the yarn and some 2 ply where two fibres are spun together.
Hanks of finished yarn - one hank measures 560 yards and the number of hanks in one pound gauges the thickness. For example 40’s quality yarn is 40 X 560 yards = 22,400 yards of yarn in one pound. 120’s yarn is 120 X 560 = 67,200 yards of yarn in one pound.
The term super refers to the micron diameter of the fibre in the yarn, so super micron numbers are:
The weight of the fabric (expressed as oz per square yard or grams per square metre) determines the right feel for the client. So 8oz, 10oz, 12oz per linear yard of cloth and so on.
Naturally the finer the yarn the more yarns there are per square metre. This doesn’t always mean that the finer the yarn the more durable the cloth. Sometimes a fine yarn fabric can lose its fluidity and be difficult to tailor, so rely on the ‘handle’ of the fabric and how it feels.
What is amazing is that in 3m of a super 120 merino wool fabric, which is what it takes to make a suit, there are about 400,000 metres of yarn.