Tools: Straight edge ruler, utility knife
When wallpapering the sloping roof of the attic, the Go/Pro non-woven wall covering fleece is separated in the "elbow". First, the slope is wallpapered and then the lower part is glued with an overlap. With the double seam cut flush cut edges are achieved that are butt joined and then the seam is rolled over with a foam rubber roller.
If the "elbow" is uneven, a pattern break can be concealed with a decorative border trim.