Merino Wool or Synthetic Fabrics....Discuss

More Info on Merino Wool

Some companies—like Smartwool, Icebreaker, IO Bio, and Ibex—deal almost exclusively with merino wool, but other manufactures (Patagonia, Arc'Teryx) have gotten into the game as well. You still pay a premium, though brands like REI, LL Bean, and Eddie Bauer offer less-expensive merino wool products. What you sacrifice for the lower-cost items? The level of thickness and fabric smoothness. The finest (referred to as Ultrafine Merino) is 17.5 micron. Ultrafine and Superfine (17.6 to 18.5 microns) is used in both fashion and outdoor apparel. Fine, Fine Medium, Medium, and Strong Merino (from 19.5 microns to 22.6) are also used in apparel, but aren't as soft.


First off, for transparency's sake, know that we are big fans of merino wool. Ever since Smartwool spearheaded the no-itch wool revolution in outdoor apparel—and made it look sexy—we've been hooked. But, we are not so fanatical to be unrealistic on value of different textiles.

Merino definitely has advantages—it maintains its warmth when wet, has a good warmth-to-weight ratio, and feels great against your skin; for those with memories of the itchy holiday sweater, you're behind the times. Merino fibers are getting softer and softer due to new methods of spinning the fine, dense wool obtained from merino sheep. The end result? Thinner, stronger, all-natural fabrics that work in both cold-weather conditions and on the hottest days of the year. It may be counter-intuitive, but we've tested thin-layer all-wool products when the mercury hovers in the triple digits and it felt great. We even love merino wool underwear.

Synthetic insulating apparel is primarily made of nylon and polyester, sometimes combined with other wicking treatments such as Cocona. The cost of synthetic apparel is generally less expensive than wool, and they're typically lighter than wool apparel. Most synthetics come from big textile mills in Asia. As such, industrial waste is a problem, although many of the big textile companies have led the charge for environmental sustainability. Blue Sign certification is one way of making sure product is made in the most sustainable manner possible.

Interestingly, though you might assume that wool is more environmentally-friendly than synthetics, according to a well-documented Life Cycle Assessment Chart distributed by Nike, wool, despite being a renewable resource, has a greater carbon footprint than many synthetics (some, like polypropylene, are made from the waste products of the petroleum industry). But that doesn't dissuade us from getting that warm, squishy feeling when we think of the happy merino sheep frolicking in the green grassy fields of New Zealand!


  • Wool has natural wicking and moisture management. It can absorb water (about 30% of its weight) without feeling wet.
  • Wool stays warmer when wet.
  • Wool is a renewable, biodegradable, recyclable material that doesn't require pesticides or herbicides for production.
  • Better safety in case of fire. Wool is self-extinguishing.
  • It NEVER retains body odors (trust us—we've tested that thoroughly, much to our own shame).


  • While most new merino wool pieces can be washed, many don't react well to a dryer. Rigorous machine washing and drying inevitably leads to shrinkage.
  • While wool fibers are fairly durable (i.e. they bend, not break), our experience is that wool garments have more of a tendency to pill or run than their synthetic cousins.
  • Moisture evaporates much more slowly than with synthetics.
  • Expense. It is not cheap to raise merino sheep and process the fiber into yarn, never mind making the shirts (refer to the sidebar for info on manufacturers who specialize in merino, as well as some lower-cost brands).



  • Never wears out.
  • Easy handling—most synthetic pieces (polypropylene, polyester, polyamide, and acrylic) can all be machine washed and dried without shrinkage or noticeable wear on fabric).
  • Fantastic wicking and quick-dry properties. Ounce for ounce, synthetic materials generally dry more quickly that wool.
  • Great stain resistance.
  • Less expensive than merino wool.
  • Feels good, but after many washings can become rough and plasticky.
  • Retains body odor, no matter what manufacturers say.
  • While some are recyclable or made from post-consumer recycled materials (like soda bottles), many synthetics rely on fossil fuel for production and are not biodegradable.
Published: 3 Jan 2011
Details mentioned in this article were accurate at the time of publication


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