Merino wool super fine

Merino wool is classified by mean fibre diameter. The IWTO scale roughly distinguishes:
Strong 23–24.5 µm · Medium 21–22.9 µm · Fine 18.6–20.9 µm · Superfine 15–18.5 µm · Ultrafine 11.5–15 µm.

Superfine merino thus marks the boundary from which wool feels absolutely non-scratchy to most people (the itch threshold starts at around 22 µm). It comes mainly from Australia (about 50 % of world production), New Zealand, Argentina and Uruguay. Superfine fleeces are frequently traded under Woolmark certification and priced at 50–200 % premiums over standard merino. Uses: sports base layers (Icebreaker, Smartwool, Devold), business knitwear, fine worsted suits, children's underwear.

• 15.0–18.5 µm (ultrafine even finer, down to 11.5 µm)
• Absolutely non-scratchy — itch threshold only starts at ~22 µm
• 50 % of world superfine production from Australia
• Base for base layers, business knitwear, worsted suits