Because of the pilling, even the most expensive sweater loses a lot of value and looks cheap.
These defects appear after several washes. It is impossible to avoid this, but there are tricks that will delay the appearance of small lumps.
To protect the item from defects, turn it inside out before loading it into the drum. Then the front side will be protected from friction, which provokes the formation of pellets.
If the item is small, you can use a special laundry bag. It will take the full "blow", but the clothes will be washed properly.
For delicate fabrics, you need to choose a delicate mode. If there are stains on your clothes that are difficult to remove, you need to choose the right products.
Enzyme-based products will help with the problem. They should contain cellulose, amylase, and protease. If pellets do appear, a special machine will help remove them.