Cotton, and why the staple matters
Washing is done at the mill, on the finished cloth, with enzymes that break down the surface of the fiber very slightly. It takes the starch out and leaves a matte, chalky hand that new cotton never has.
The fabric
Washed cotton
Cotton that has been through the wash before you own it, so it arrives already soft.
Pre-shrunk, so it stays your size
The wash also does the shrinking before the cloth is cut. A duvet cover that has not been pre-washed can lose two inches in its first cycle at home, which is how covers end up too small for the insert.
Out of the dryer, onto the bed
It comes out looking lived-in, which is the whole idea. Nothing to iron, nothing to fuss over. It softens a little more over the first year, then settles.
Questions about this fabric
Is washed cotton the same as linen?
No, but it borrows the part people want: the dry hand and the relaxed fall, without the first year of stiffness and without the price.
Will it keep shrinking?
It should not. The shrinking is done before the cloth is cut. Wash cold, dry low, and it will stay true.
Does it look wrinkled?
Softly, yes. It is meant to. If you want a smooth bed, choose percale or sateen.