Solid Mortice Handle. solid mortice handle is a type of door handle that is fitted into a recess or cavity in the edge of a door. It is usually paired with a mortice lock, which is a locking mechanism that is also installed inside the door. A mortise lock is a locking mechanism that is installed inside the door and requires a key to operate. Solid mortice handles are durable, corrosion-resistant, and have a sleek appearance.