Pilling — those small fabric balls that build up on a shirt’s surface — gets blamed on the washing machine almost by default, but shoulder-specific pilling has a second, very common cause: a backpack strap rubbing the exact same two spots on a shirt for hours a day, every school day.
Why the shoulders specifically
Backpack straps sit directly on the shoulders and create repeated, concentrated friction in a narrow band each time the straps shift while walking, sitting down, or adjusting the bag. That’s a much more localized and repetitive friction source than normal wear, which is why pilling on a backpack-wearing kid’s shirts often shows up specifically on the shoulders rather than evenly across the whole garment.
Washing still plays a real role
Machine washing does contribute to pilling generally — friction against other garments in the load, especially with a full or overloaded machine, roughens fiber surfaces over time. It’s a compounding factor on top of backpack friction, not a separate, unrelated cause. A shirt that gets both heavy backpack wear and washing done reg ularly with a packed machine is getting hit from two directions at once.
What actually helps
What pilling isn’t
Some pilling over time on any cotton shirt with regular wear is normal and not a sign of a defective garment — it’s a natural result of fiber friction, and the goal is reducing it, not expecting zero pilling ever.
Common questions
A backpack strap rubbing the same narrow area for hours a day, every school day, is a very common and often-overlooked cause. It’s more concentrated friction than normal wear, which is why it shows up specifically there rather than evenly across the shirt.
Both contribute. Washing — especially in an overloaded machine — roughens fiber surfaces through fabric-on-fabric friction, and backpack straps add a second, more localized friction source on top of that.
Not automatically — some pilling over time is normal fiber wear on any cotton garment. Higher-quality, more tightly spun cotton (like ringspun) resists it better than looser open-end cotton, but zero pilling ever isn’t a realistic expectation for regularly worn clothing.
Read more about how we choose fabric in Our Approach, or check the FAQ for care details specific to our tees.