What is Merino wool made of? Proteins composed of amino acids and natural compounds. Merino wool is a natural, renewable fiber—meaning one sheep can grow four to five pounds of wool per year. Plus, this fiber has evolved over the years to keep sheep comfortable in harsh environments. These happy animals hang out in temperatures that range from 5 degrees to 95 degrees—no problem. It’s a pretty amazing fiber.

What is Merino wool really good at? Helping keep your body at a stable temperature. When it’s cold outside, the natural crimps and bends in its fibers trap air, insulating you. When it’s warm outside, it transports sweat quickly away from the skin, helping to keep you cool and dry.

This benefit of wool gets a bit technical—so bear with us. Merino wool transports sweat and moisture away from skin as a vapor. Merino fibers are inherently porous. They’re composed of little plates that moisture vapor can get in between—meaning you're not left feeling wet, cold, and clammy after a workout. Synthetic fabrics are not porous. They usually wick sweat when it’s already a liquid, and then your body has to heat it up to evaporate it—making you feel clammy in colder weather. Merino takes a step out of the process, which helps you stay warm and dry when you’re moving and playing outdoors.

Sometimes it’s really cold outside and you need to layer. By using all Merino wool when you layer, you create an escape route for sweat and excess heat. Each layer of Merino works to transport sweat away from the skin to the outside of your gear while it’s still a vapor (pre-sweat)—helping to keep you warm and dry. Throwing a synthetic layer in there mucks up the sweat-vapor escape route and creates a detour that might increase your chances of getting cold and clammy.

Merino wool is unique in that it absorbs odor caused by bacteria—trapping their smell and keeping them from building up. This means you can wear Merino wool odor-resistant clothing for longer without having to worry about smelling. Merino wool is great for traveling or longer treks when you may not have as much room to pack.

What is Merino wool better at than traditional wool? It’s super-fine and soft. A single Merino wool fiber is ⅓ the diameter of a human hair. It’s so fine, actually, that when it brushes up against skin, it bends out of the way. It can’t be prickly like other wool fibers because it can’t stand up to the weight of itself. So it’s soft. Really soft.

Merino wool disappears after about 12 months in the ground. That means that, when you’re done with your gear, the earth will take back this fibrous protein composed of amino acids—releasing carbon and nutrients back into the soil.

Most outdoor gear spends at least some time around campfires. Merino typically won’t melt or burst into flame. Nylon starts to melt around 320 degrees and polyester starts to melt around 452 degrees.