I've found a few different definitions:
Automotive def: Lines in the body where two body parts abut each other, such as where a door meets a fender. Can also be a seam where two immovable parts meet i.e., plastic bumper cover meets quarter panel.. which would make sense in this story. With the 2 ml.
Shutlines may also refer to the relationship between straight and curved lines in a design. For example, a technical drawing teacher may advise against mixing straight and curved lines in a design...which could also make sense. Jay is the straight and narrow type and shin veered off on a curve to survive.
A shut line is the clearance gap between two adjacent surfaces, such as the gap between a door opening and a car body panel, or between a lid and the body of a tea kettle.....who knows. But they all make sense to me.
Does anyone know what shutline means? I haven't seen a clear definition and was curious what exactly it means