Geometry
Crease
A crease is a controlled deformation of board that guides a fold without cutting through the material.
What it means in packaging
Creasing helps a panel bend at the intended location. The tooling and channel must suit the board and its grain direction. In dieline workflows, score or crease lines are often used as fold references, but the converter determines the actual tooling.
A practical example
A rectangular carton uses parallel body creases so its flat strip can fold into four walls.
What to check
A simulated hinge needs a corresponding manufacturing fold instruction. Inspect a sample for cracking, spring-back and fit.