A consistent thin line in the same place on every frame usually points to a scratched negative, not a Noblex-specific issue. Based on the descriptions, the most likely cause is a dry scratch on the emulsion side of the film, probably from grit or debris in the camera film path or possibly around the film cassette/light seal. Rewinding could also contribute if something was rubbing the film.

A lab or scanner problem is less likely here: scanner issues tend to look more uniform, and a very thin uneven line usually indicates damage on the film itself.

What to do:

• Inspect the negatives closely to confirm the line is physically on the film.
• Clean the camera’s film path carefully.
• Use a soft brush first, then gentle air to remove dust/grit.
• Check the cassette area/light seal for debris on future rolls.

If the mark is on the negatives, the damage happened before scanning. If it is not on the negatives, then ask the lab about scanning.