Black packer. 2mm. If head is full length pull door shut to latch, pin head stop up with black packer between door and stop, not pushing too hard against door. Then leg stops on hinge side hold the packer and nail at roughly the hinge positions then open the door and hold your 6ft level against the stop, pull it tight to the level then you know its straight. Few more pins. Latch side repeat keep it at 2mm if your latch is adjustable. Knock the inside part of latch forward a bit before final fix with ironmongery so it pulls in tight to stop. On site they just out the stops in a fixed distance from the door edge of the lining ie 37mm but thats more for production work ain't got time to mess with keeps.