Are they made out cotton? do they shrink and lose their shape after washing? do they come smaller than expected? i usually wear l or xl.

It’s a cotton mix. Mine have not shrunk at all or if they did, I have not noticed because though they are true to size, they are ever so slightly on the loose side. I would buy the size you most usually get. If in most brands, you are a large, with the exception of a few needing XL, I would recommend getting the large. And if you mostly get XL with a few brands requiring large, get the XL. You would probably be fine with a large though.

To amazon essentials, any chance of these being made in plus sizes? (1x, 2x, 3x) just for the record, xxl is not the same as 2x. trust me.

I'm plus size. I just order one size larger than usual and it works for me. To be honest though I prefer my clothes to be roomy and not fit exactly (personal hang up) and when ordering one size up they fit.

What is the length in inches from neck to bottom (in back of shirt) for size large? Thanks much if anyone is willing to answer.

26 inches. I haven't worn/washed mine, so the measurement is before washing. I ordered the 2-pack in white. Very pleased with my purchase.

Are they stretchh enough and deep enough v neck to breastfeed in them?

I’m able to pull it down enough to breastfeed out of the top. They’re really stretchy! I’m 5’7 150lbs 34DD, I usually wear a medium but ordered a large with hopes I’d be able to BF in it this way, worked out perfectly.