I have about 20 shirts at any point. When they tire out, I cut them up for rags.
Currently, of about 20 shirts, 1 is hemp, 19 are various cottons and synthetics.
The hemp shirt is tied for the oldest. I've worn and washed it hundreds of times. It was never the prettiest, or the most brightly-coloured, but it has retained its colour and shape. It's comfortable, light, but warm and breathable. I didn't like it when it was gifted to me, but over the years it became one of my all-time favourites.

This slideshow seems to have some decent info if you're interested: