They may shrink a little bit and become stiff, or the color may fade after washing multiple times.
That depends totally on how the fabric is made. If the fabric is woven, like broadcloth or percale, it will not stretch. If the fabric is knitted, like a T-shirt, it will stretch.
I had the same question.we chane cotton fibres to cotton fabric by doinng three(3) proccess(i)ginning,(ii)spinning&(iii)weaving
5%
One whole size,if you wear a large buy an x-large etc