There is only one primary method of binding used in Legal Pad Notebooks and Legal Notepads with this being casebinding, casebound notebooks & pads are exceptionally durable with a strong stitched and glue bonded seam that the paper is attached to. Notebooks and pads are typically either headbound or sidebound.
As this binding method of bonding paper to the pad or book is so strong many notebooks or notepads would have perforated sheets that would allow the user to remove an individual sheet with ease.