Coptic stitching is one of my go-to bindings. It’s terribly easy and is useful for so many projects. I enjoy the straight lines and chain stitching that accentuates the open spine.
Lovely coptic binding nice and straight, from The Laurel Tree
Fantastic coptic with an added caterpillar stitched on the covers, from Katie Calak
coptic binding in a zigzag variation, from Garlic Harvest Studio
Up close and personal with another coptic variation, from Cailun
Video Tutorial here