a combination of material selection, thickness, open area and unperforated borders can all influence the level of flatness of the final perforated sheet.
![Perforated Sheet Straight from the punching machine](https://www.metrixgroup.com.au/wp-content/uploads/2021/08/perforated-sheet-straight-from-the-punching-machine.jpg)
Perforated Sheet Straight from the punching machine
![Perforated sheet after 2 passes of Tension Levelling](https://www.metrixgroup.com.au/wp-content/uploads/2021/08/perforated-sheet-after-2-passes-of-tension-levelling.jpg)
Perforated sheet after 2 passes of Tension Levelling