Merino Wool Abrasion & GORUCK Bags

One of the big criticisms of merino shirts for general wearing is whether or not they can hold up to abrasion. Typically the concern is less about wearing a hole in the shirt and more about the shirt pilling when doing normal things (like wearing a backpack s of particular worry to those who like to travel in merino wool shirts — as most bags are heavy when traveling and abrasion can be really high. I am ling at this throughe lens of wearing this type of clothing while commuting and traveling — not while hiking and doing more outdoors oriented stuff.

The Test

In order to test what’s real and what is paranoia, I wore the same Smartwool 100% merino t-shirt while I rucked (working out by walking with a really heavy backpack on) for for weeks straight. A total of bout 60 miles of wear with a 30 lb GORUCK bag on my back. GORUCK’s bags are among the most abrasive bags on the market, and the added weight with the sweat from the workout makes it among the most adverse tests you can put these shirts through. During the course of the testing I only washed the shirt once per week and hung it to dry.

This should simulate the amount of travel the average person does in a year, or a partial commute with backpacks. Most people won’t travel with a backpack this heavy, but this should accelerate any issues with pilling.

The Result

In the first week I noticed pilling where the bottom of the bagand straps sat on the shirt. By the end of the test there was only minimal pilling on the back but it seemed to disappear on the shoulders. No holes or any otherwise noticeable problems with the shirt. After each wash, most of the pilling seemed to disappear as well.


Cotton shirts also pill in these areas as well, so a large part of the talk around this pilling seems to be paranoia as it will tend to happen to most shirts. However, it does give me pause when wearing a GORUCK bag and something like Outlier’s Ultrafine Merino T-shirt. Having said that, I don’t think there’s a ton to worry about, and I still don’t hesitate to travel with my GORUCK and merino clothing.

Yes, with a lot of use with an extremely abrasive bag, you’ll see some pilling, but certainly not enough to otherwise ruin a shirt. This isn’t the nature of 100% merino wool.

For instance, compare this photo of my Outdoor Research Sequence shirt which is a merino wool blend:

The pilling is far worse on this shirt, not just in the areas where my backpack wears during rucking, but in any spot where there’s friction. It’s a shirt prone to pilling. I have no doubt that some shirts pill more than others, but I have seen no evidence that 100% merino wool shirts are more prone to pilling, or less durable, than any other natural fiber shirts.

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Merino Wool Abrasion & GORUCK Bags