wool/linen wide enough for long sleeves

[M. Demetrius]

Apparently, there were some 1st century tunics with sleeves sewn on, but much more common would be two simple rectangles, in which the "sleeves" are derived by the belted middle, rather than being separate pieces. Sewing is greatly reduced, always an advantage (for strength and the seamster) for the hand sewn garment.

If you were weaving one of these in one piece, it would not be a big problem to pull up some of the warp at the neck hole, and tie the neckhole open on both sides. Then it's just woven in, not cut and faced. You'd have to plan for that, though, or your warp in the middle might come up short at the bottom hem.

I'm not sure the Romans used facings...more likely turned and hand hemmed finishing techniques. I have a picture of that edge treatment on some other topic thread.