Natural indigo is the blue dye extracted from the leaves of the Indigofera plant.

Here are more men’s sweaters that I’ve found that feature 50% or more yak wool:

Here is a list of companies that make wool knitwear for men:

Camel wool is a very soft, insulating fiber. It ranges in size from 15 to 22 microns — putting it in the ultrafine or superfine categories.

Yak down is a very warm fiber that’s also lightweight and soft. It’s a more affordable alternative to the rare qiviut (musk ox down).

This is a list of clothing brands that make use of organic fibers and non-toxic dyes:

Any wool fiber that has a diameter of 20µ (microns) or less will feel very soft to the touch.

This is a list of knitware manufacturers and stores:

Here is a list of Canadian Clothing companies.

These are the warmest hoodies I could find in 2019:

Hemp is an ideal material for shoe making. It is one the most durable plant fibers. Hemp is also anti-microbial, temperature regulating and breathable.

At Reactual I like to feature independent clothing companies in the US.

For maximum warmth without bulk I recommend yak wool sweaters

Qiviut (pronounced “kiv-ee-ute”) is the name for the downy hair of the musk ox. It is the warmest fiber in the world — about eight times as warm as sheep’s wool.