If you don't have the luxury of a large gear bag when you travel, saving space might be important to you. In that case, you might want to consider a folding mask. Although they don't feature a hinge that really "folds" them in half, folding masks are masks that lay down flat for easy packing. Sherwood's Mako mask is an example of a folding mask.

The Mako features a subframe, which means that rather than attaching the mask strap to the flexible silicone skirt, the strap is attached to a small piece of rigid material (called a subframe) that's attached to the mask. This "virtual frameless mask" provides greater stability and a more secure fit than some other frameless masks. Featuring an easy-access nose pocket for quick-and-dirty clearing, and a single tempered-glass lens, the Mako comes in a variety of styles and won't take up too much space in your gear bag.

And if you're wondering, Sherwood's website claims the Mako is the "coolest looking mask you can buy." That's got to count for something.