what is optim wool?
a few years ago I was visiting the showroom of motivmfg., operated by bespoke tailor daniel gu.
he talked about a natural fiber waterproof fabric, which was pretty unknown to most people and hardly used in the garment industry.
developed under the guidance of woolmark, the global leading authority on wool, in collaboration with the only factory that can actually make that technique work.
I was curious yet skeptical. surely there was a membrane or a coating involved.
how else can it be waterproof?
my skeptical views were quickly washed away.
in my hands was a 100% merino wool fabric with a softness and drape which I've never seen in these type of functional fabrics.
daniel explained a bit more.
a fibre stretching technology stretches the merino wool fibre for a good 40 meters and letting it set, and then spun into yarn before being woven to create a wind and water resistant fabric free from PFAS, membranes or fluorocarbons.
the extremely high thread density in warp and weft using merino wool yarns that were stretched and temporarily set, is at the core of the optim wool technoloy.
after wet-finishing the fabric, the stretch is released causing the yarns to contract which then gives the fabric its extreme tightening in the fabric structure and thus the incredibly dense, functional, waterproof fabric.
as an eternal skeptic, I decided to test it myself as well with one of the motivmfg. outerwear designs from 2025, the Hubertus field jacket. having been caught in a few torrential rains late august and early september, I can confirm that it is indeed waterproof.
although the waterproofing column is less than with technical, synthetic membrane coats (usually around 20,000mm such as norwegian rain), the optim wool holds up extremely well in unexpected rain showers. in comparison, the waterproofing column of natural fibre optim wool sits around 1,000mm rainfall in 24 hours. not too bad for a textile that doesn't use a membrane or forever chemicals.
optim wool has now been developed in different weights, offering makers such as motivmfg. to extend their design range with specific winter editions.
for the autumn/winter 2026 season we put together an optim winter wool range in 2 outerwear pieces and 1 adjustable trouser: moebius jacket, bayonet bomber, and mod. kinetic trouser.