We've used Oxford cotton on four of our shirts so far; white and sky for the recent Clough shirts and white and marine stripe for the first Backtor shirts that we made back in December. The cloth has been woven for us in a Lancashire mill which we work closely with.
Oxford cloth has a basket-weave structure. The threads are interlaced to form a criss-cross pattern which looks like a checker-board up close. There are a few types of Oxford cloth; Pinpoint and Royal Oxford are the formal variants which tend to be used to make dress shirts. Our shirts are made using plain Oxford which is more durable, better wearing and better suited to casual shirts which is why we use it.