A Micron (μm) is the unit used to measure the diameter of a wool fiber. The smaller the Micron measurement, the finer and softer the wool. The finest wool is considered anything less than 24 μm. To put that into perspective, the average human hair measures around 75 μm thick.
Fine Wool Knitwear Explained: Microns, Ply, Gauge, and Grade
Microns (μm)
The longer and thinner the wool is, the more durable the yarn is. Not all wool is created equally; in fact, it is a very complex fiber. While there are certainly other variables at play, these are the most measurable metrics availble to grade fine wool.
Fine Wool Quality Grading Scale
Fine wool (Cashmere Wool, Merino Wool, Alpaca Wool, etc.) is graded based off of two main facors: fineness (Microns) and length. After herders have collected raw wool, it must be sorted into 3 separate categories: Grade A, B, and C.
GRADE | FINENESS | LENGTH |
A |
Finer than 19 μm |
Longer than 36 mm |
Grade A is the highest quality of wool. It signifies the softest and most durable natural fibers available. All of our wool garments are made with Grade A wool.
GRADE | FINENESS | LENGTH |
B |
Ranges from 19-24 μm |
Ranges from 29-35 mm |
The majority of knitwear on the market is made with Grade B wool. This wool is of great quality but is slightly less soft and durable than Grade A.
GRADE | FINENESS | LENGTH |
C |
Thicker than 24 μm |
Shorter than 28 mm |
Grade C wool is much less soft and durable than Grade A & B. Most fast fashion brands use Grade C. It is commonly used in cashmere garments priced under $200.00 USD.
Gauge
Gauge (gg) is a measurement that defines the number of stitches per inch on a knitted garment. Most knitwear comes in a range of 3gg-16gg.
Simply put, the lower the gauge, the heavier and warmer the garment will be. For example, a 3-gauge sweater will have a chunky look while a 16-gauge sweater will be much thinner and lighter.
3gg-7gg
Perfect for cold weather
7gg-12gg
Perfect for cold and cool weather
12gg-16gg
Perfect for warmer weather and layering
The most durable knits tend to be around 5gg-12gg as this allows for a thick composition while still using Grade A wool.
Ply
Plainly stated, ply is the number of strands twirled together to create a single thread of yarn. Knitwear is most commonly produced in 2-ply or 4-ply.
Generally, 2-ply is best suited for fine wool like Cashmere or Merino Wool; while higher plies such as 4-ply add additional weight, but do not indicate additional warmth or quality.