Our masks are flexible, and fit off the human skull. regardless of whether you think your head is very small, very large, or fairly average, they will fit. You may end up opening them up a tiny bit over the bridge of the nose, or closing them down a tiny bit in the same spot, but this can easily be done by hand.
The wonder of a copper mask is in the strength and give of the material. Because it is so strong, the mask can be very thin- this makes it both very light, and makes it possible to fit as a second skin. These won't block your peripheral vision the way a leather, paper maiche, or plastic mask would. They can be very comfortably worn all day and night- no worries about sweat or rain causing them to soften and lose their shape. Rinse it with clean water at the end of the night before putting it away. They can stand up to anything you throw at them. As for packing? Throw it in your bag. If you're checking the bag, maybe stuff a balled up pair of socks where your forehead would go. Easy.
Not planning to wear your mask? He or she won't mind. They can hang flat against a wall, or sit on a shelf.