Please note that while the openwork masks like this are plenty wearable, they DO need some extra protection for packing; I recommend, for transport, giving them their own box; if space is at a premium, you can use your socks or tshirts of whatever as packing material, but the mask IS squishable. If the mask's squishable-ness comes up while you're wearing it, the mask will be the least of your worries. Do not squish your head.
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. All colours are created by carefully controlling heat and the metal's access to oxygen throughout the process and are both durable and archival. 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? They won't mind. They can hang flat against a wall, or sit on a shelf.