What is Unfilled Finish Glass Defect?

What is Unfilled Finish Glass Defect?

By: Berlin Packaging Specialist
Date: November 11, 2019

Unfilled finish is a type of glass defect during the manufacturing process of glass bottles.

The finish is not completely regular; the thread profile has not been formed properly. There is glass missing from the top surface.


  • Defective sealing: risk of leaks, product deterioration, problems in vacuum filling.
  • Sometimes this can be just a minor defect (m), for instance unfilled finish on the bead of a cork mouth.