First, check if the folder is applying enough glue. Too little glue means a weak seal—just increase the amount slightly.

Then, inspect the carton material. Avoid paper that’s too smooth or too rough—glue won’t stick well to either.

Finally, adjust the folder’s temperature a bit. It helps the glue bond tighter.

After these adjustments, boxes will have neat, secure seals that hold up even during bumpy shipping. Have you had other sealing issues with your carton folder? How did you fix them? Share in the comments!