· Super Moderator
While it depends upon what you mean by open, in general, they shouldn't be. But if there's too much waist suppression (I.e., a fashionable fit.) they pretty much have to be.I just got a ton of sport coats and suit coats tailored, and on most of them the side vents do not flare, but they do separate slightly so the vent opens a bit. Is this okay, or does it mean they're ill fitting? The coats were taken in a bit and look fine from the front, but I have noticed a separation in the vents. Any thoughts on this? Is it just the flare that's frowned upon, or is it inappropriate for the vents to separate as well?