Hidden fasteners, also called hidden hangers, are the most popular way to install gutters. With this system, the gutter is fastened directly to the fascia. Hidden fasteners are used every 16 to 24 inches on average and give the gutter its strength and support. Aptly named, hidden fasteners are concealed inside the gutters and are not visible from the ground, creating a more continuous look and amped-up curb appeal.