Cotton shrinks not from washing, but from a sharp change in temperature. If an item was in hot water and then in a hot dryer, the fiber contracts, and you won’t be able to restore the original size.
Three rules
Thirty degrees. That’s enough for everyday dirt. Hot water is needed only for stains, and it’s better to treat them spot by spot.
No dryer. The simplest way to keep the size is to dry on a flat surface. The item doesn’t stretch under its own weight and doesn’t shrink from hot air.
Inside out. This way the front side suffers less: fewer pills and preserved color.
If the label says “hand wash,” a delicate cycle with a 400 rpm spin usually works too.
And one more thing: don’t dry cotton on a radiator. The fiber overdrys, the fabric becomes stiff, and the collar loses its shape.
