Wool products are incredibly useful from autumn through early spring. If you enjoy hiking or cycling, you’ve likely experienced the benefits of merino wool base layers and mid-layers for yourself.
At Circles, we carry a wide range of wool items and always recommend them as essential gear for rides during this season.
However, many people still feel that wool is "a hassle to care for" or are "unsure how to wash it." So, I’d like to explain the characteristics of wool fibers, the principles behind why they shrink, and some simple care methods. Once you understand these, you'll know exactly how to look after your wool items!
We’ve finally released our Merino Wool T-shirt from RAL this season, so if you're interested, please use this article as a guide!
A material that has long been a part of human life
Wool has been used for workwear, such as by fishermen, since ancient times, and has long been a staple in outdoor settings.
Later, with the invention of polyester fleece (a market created by Patagonia, of course), which offered superior insulation and quick-drying properties, wool was largely replaced and considered an outdated, classic material. However, it regained appreciation with the spread of merino wool in the early 2000s.
Now that it’s back, what actually makes these two materials so different?
Characteristics of polyester
Polyester is a synthetic fiber derived from petroleum. It became widespread after World War II because it is easy to produce and relatively inexpensive. Because the fiber itself does not absorb moisture, it utilizes capillary action to quickly wick sweat and other moisture away from clothing, making polyester vastly superior in terms of quick-drying performance.
During production, the shape of the fibers can be artificially altered to add various functions. It is also durable, so you can throw it in the washing machine without worry.
These are the strengths of polyester. However, synthetic fibers are thin and prone to static electricity, which makes them difficult to clean of sebum, hard to remove stains from, and prone to trapping odors. While some come with anti-odor treatments, these added functions are not permanent and degrade over time.
Characteristics of merino wool
Wool, including merino wool, is an animal fiber. Being an animal fiber means it is composed of the same proteins as our hair.
Compared to plant-based fibers like cotton or linen, its strengths lie in superior temperature regulation, insulation, and moisture management. Because it is the same protein as our skin, it offers better moisture absorption and comfort, and has natural deodorizing properties, making it comfortable even when worn for long periods.
It serves as an insulator under a shell or as a breathable base layer on its own, allowing it to adapt to environmental changes and reduce the discomfort of long-term wear. It’s easy to see why it is used in so many different activities.
Recently, materials that combine these two to leverage the benefits of both have also been developed, and it seems there is still more innovation to come in the world of textiles.
Why does wool shrink?
While wool may seem perfect, its only tricky aspect is care. Wool is susceptible to changes in shape; just as our hairstyles change when we get a perm or use a curling iron, the shape of wool fibers can easily change depending on the care environment.
When magnified, wool fibers have a cuticle-like structure similar to human hair. This structure is what provides its various functions, but it also means the fibers can tangle together, causing shrinkage, or become matted and wear away, which is the cause of pilling.
Shrinkage particularly occurs when moving from a wet state to drying, as the fibers tangle more easily. (This is the same principle as how your hair gets messy bedhead if you don't dry it with a hair dryer after washing.) High heat also causes changes to wool—much like using a curling iron on your hair to create waves or curls. Applying heat is another cause of shrinkage.
Ordinary household laundry detergent can also be a factor in shrinkage.
The reason is that, much like human skin, the skin and hair of most animals are weakly acidic. However, most common household laundry detergents are weakly alkaline.
Washing wool or animal fibers with a weakly alkaline detergent is like washing your own hair with bar soap. You know how your hair feels squeaky and gets tangled when you wash it with soap, right?
This happens due to the relationship with pH levels that we learned about in elementary school science class. The cuticles, which are usually closed, open up as the pH shifts toward alkalinity, making the fibers feel rough and prone to catching. In wool fibers, these open cuticles tangle together and tighten, accelerating shrinkage. (Conversely, this phenomenon is used to create felt fabric; for example, OTOPUKE KNIT hats are made by intentionally shrinking knitted fabric using this principle.)
By the way, hair washed with soap can be restored by rinsing with citric acid or diluted vinegar. This effectively balances the pH back to normal!
How to keep your wool products for a long time
To summarize the above, the major causes of wool shrinkage are:
1: pH change from weakly acidic to weakly alkaline
2: The washing and drying process
3: High-heat drying in particular
In other words, if you wash it with standard household detergent and toss it in the dryer... it will end in disaster (I speak from experience). Now that you understand the principles, here are some simple washing instructions.
Use neutral detergent for wool!
Always use a neutral (pH-balanced) detergent when washing wool and animal fibers. This prevents the pH shift mentioned above. This is the secret to making your items last. There are many neutral detergents, but "Emal," available at pharmacies nationwide in Japan, is easy to find.
Also, make sure to close all zippers. Zippers can whip around in the wash, potentially damaging the surface of other items in the load. Putting items in a mesh laundry bag is the best and most disciplined practice.
Don't use fabric softener!
Fabric softener remains on the surface of the material, which can prevent it from performing its natural functions. (This is why the scent of fabric softener lasts so long.)
Use detergent that contains only cleaning agents!
Looking back at the ingredient label I showed earlier:
Bleach, softeners, and optical brighteners included here will all impair the functionality of the material. Be aware that some detergents contain fabric softener.
This is the label for Emal. Use a detergent that is "neutral" and free from these other additives.
Stretch it gently!
Since the fibers will at least be slightly tangled in the water, gently stretch the garment back to its original shape. (Personally, I feel that stretching it at this stage is quite safe. Stretch it in the direction you don't want it to shrink!)
Lay flat to dry, or drape directly over a drying rod!
Shrinkage is most likely to occur during the drying process. Additionally, long-sleeve items can get shoulder bumps from hangers depending on the shape, so I recommend laying them flat in the shade to dry.
However, this method takes up a lot of space, so draping it directly over a laundry rod is more realistic. Sleeveless items might be fine on a hanger. (If you don't mind the hanger shape marks, hangers are clearly more space-efficient. Personally, I don't mind, so I just use hangers.)
Unless it's something you bought too big and actually want to shrink, staying away from dryers is the wisest choice for your peace of mind.
If you follow these washing methods correctly, wool will be a great companion that always performs at its best. I hope you enjoy your merino wool products!
If you would like to know more, you can learn more about wool by clicking the "Source" links in each image or the links below.
Tokyo Cleaning Business Association, "About Warm Fibers: Wool"
Senken Plus, "Essential Knowledge About Wool"
Yofukuya no Issho-mono Blog, "Fisherman's Traditional Clothing"
Let's enjoy our activities with wool!