WeatherWool does not use any superwashed fiber.  However, prior to Batch 9 (for our woven products) and Batch 12 (for our knits), we did use some superwashed yarns. 

You can easily find lots of superwash info on the web.  And, of course, you'll find people arguing both sides of superwash.

Superwash -- superwashing -- is treating wool chemically and/or physically so that it can be machine-washed without fear of shrinkage.

BUT ... problems with superwashing -- both performance-related and environmental -- have driven our decision to completely avoid superwash.

Prior to Batch 9, we used superwashed warp (warp runs lengthwise through a bolt of fabric) fiber/yarn in our Fabrics.  Prior to Batch 12, we used superwashed fiber in our knitted products (Watch Cap and Neck Gaiter, plus the cuffs of our Hooded Jacket).

All Batches after Batch 8 are completely free of superwash.  This was a (winning!) gamble for us, because there was no way of knowing for sure until we tried.  We are very happy with the results, both woven and knitted.

There are other technical changes we implemented with Batch 9, all of them were something of a gamble, and more expensive (as usual), but all of it seems to have been a big win.  I should probably write up another page on all this ... The Batch 9 page has info, but should be generalized because this is now our SOP.

When we started this company, we did not know about superwashing.  We have always made our weft yarns, which are about 80% of the weight of our woven garments.  And we never superwashed our weft fibers.  But we were not large enough to make our own warp, which requires purchase of at least 40,000 pounds (18,000 kg) of greasy (raw) wool to start.  So we had to purchase our warp yarn, and I think all the commercial warp was superwashed.  Superwashed is "the norm".

As far as I know, any woolen garment that offers machine-washing (home wash-machine and dryer) is superwashed.   And that means almost all woolen base layers are superwashed.  Very significantly, American garment-labeling law does NOT require disclosure of superwash.  You will normally need to visit the website of a garment maker to find out whether their wool is superwash, but even then it is not usually mentioned. (Improvements in superwashing techniques is usually toward more eco-friendly materials.) But if the care label does not warn against machine-washing, you can assume the wool is superwashed.

Important Note: The following material is based on info I found on the web. I'm not claiming any expertise. I'm only trying to present what I've read elsewhere because superwashing is an important topic.

Wool is scaly, kind of like a snake. And those scales enable wool to absorb and then adsorb water vapor but repel liquid water, which is key to WeatherWool's All-Weather performance. But the downside to wool's "scaliness" is that the scales can ratchet against each other when agitated ... and the ratcheting effect only goes one way. So the yarns can shrink when agitated, and obviously shrinkage is a problem. (The scales also lend strength to wool yarn because the scales prevent fibers aligned in opposite directions from sliding across each other.)

Superwashing eliminates the ratcheting in one or (usually) both of two ways. One general method of superwashing involves the use of acid baths to eat away at the scales ... no scales, no shrinkage due to ratcheting. Another superwashing method involves coating the wool fibers with a synthetic polymer so that the scales are sort of filled in and smoothed over, and again, the ratcheting is eliminated.  In most cases, superwashed-wool has been put through and acid-bath and then coated with synthetic polymer.

Below left is a photo of an untreated, natural wool fiber. The scales of the fiber are sharply defined. Below right is a photo of a fiber superwashed in hydrochloric acid, showing how the scales have been etched away. At bottom is a fiber superwashed with polymer. The polymer coats the entire fiber and the scales are smoothed over somewhat.

 

 We do not  know where these photos came from. We owe someone a PLEASE AND THANK YOU, at the very least. If anyone knows who we can contact, we'd love to hear from you, please. Kathrin from Germany has seen these same photos used by Woolmark, and suggests they own the rights. This would make sense, and THANKS! to Kathryn for pointing us to Woolmark. Woolmark, the trade group from our friends in Australia, has provided a lot of great material!

 

There are many variations and overlap between/within the two main methods of superwashing, but the goal is to enable wool garments to be cleaned in a standard wash machine, without shrinking, by eliminating the tendency of the scales to ratchet.

BUT ... Of course there are disadvantages to superwashing, else it would always be done.  Here are some effects on the wool itself:

• Wool doesn't have those scales for no reason. The spaces between the scales enable water vapor to infiltrate a wool fiber, and enable the fiber to exclude liquid water ... So vapor coming off the body, and humidity from outside air can be slowly taken into the fiber, but the water from rain or even a swim is greatly inhibited from entering the fiber. Covering the fibers with polymer reduces or eliminates this behavior. Etching the scales away with acid also changes the way the wool handles water.  We would hate to eliminate the ability of our garments to pick up vapor!!
• Superwashed wool is much more hospitable to bacteria than natural wool.  Superwash is much more prone to odor, and needs to be cleaned more frequently and more harshly than natural wool
• Superwashed fiber does not handle moisture nearly as well as real, natural wool
• Covering or eliminating the scales weakens the yarn because scales prevent yarn from stretching and breaking ... when fibers are lined up in opposite directions, the scales prevent the fibers from slipping past each other ... the scales hold the yarn together. Some knitters describe yarns superwashed with polymer as slippery, and they are well-known to stretch over time.  We need our yarns to be strong and our garments NOT to stretch!
• Some people find the feel of polymer-superwashed fiber to be uncomfortable ... much more like a synthetic fiber ... which makes sense, given the synthetic coating on the wool
• Superwashed wool loses the "memory" ... a woolen garment over time will conform to the wearer, but superwashed wool does not have the garment memory
• Superwashed fiber is more prone to pilling
• Superwashing involves chemical treatments that many would prefer to avoid.  YEAH ... some types of superwashing are illegal in the USA and most superwashed garments that are sold in the USA were superwashed elsewhere
  

Other downsides of the superwash process:

• Superwashing involves chemical treatments that many would prefer to avoid.  YEAH! ... some types of superwashing are illegal in the USA and many (even most?!) superwashed garments that are sold in the USA were superwashed elsewhere
• Some people believe our skin can absorb the polymer coating as bits of it separate from superwashed wool
• Superwashing produces wastewater that contains some very nasty compounds and cleaning the wastewater can be difficult/expensive to the point that, according to some, the wastewater is NOT properly cleaned, and noxious chemicals are discharged into the environment
• The people who perform the superwashing are exposed to some bad stuff
• Advocates of superwash wool claim that it biodegrades, harmlessly, more quickly than does natural wool.   This claim surprises me ... Some will say the superwash wool breaks up into tiny bits in the environment and the wool biodegrades whereas the plastic lives on forever

For us, once we gained some awareness of the situation and the size necessary to avoid superwash, there really was not much of a decision to be made.

Sorry, but probably I should repeat!! ... the information presented here is the best I can figure out after doing some research. I'd be more than happy to hear from people who can make it better.

THANK YOU

 

8 April 2025 --- Ralph