Skip to main content

What went wrong?

Numbers, letters or blotchy spots from the backing paper show on my 120 negatives

Negatives and slides

What you're seeing

Frame numbers, letters or other printing from the backing paper, or a blotchy mottle, appear as slightly denser or lighter marks on 120 negatives. They may cross frame lines and sit in the same place on several turns of the roll.

Check this first

Check this first

Check the film's expiry date and how the roll was stored before and after shooting, especially warm or damp places.

Likely causes, most common first

  1. 01

    Backing paper reacting with the emulsion (wrapper offset)

    Common
    How to tell
    Marks match the printing or texture of the backing paper and are offset by the roll's circumference, not aligned with frames. More likely on old film or film kept warm or damp. Ilford says this affects 120 only, not 35mm or sheet film.
    Test it
    Look at the negative on a light box beside the backing paper from the same roll: if the marks match the paper's printing in reverse position, it is offset.
    The fix
    Store 120 film below 20 °C, away from humidity, in its sealed wrapper. Process soon after shooting and use it before the expiry date. Report fresh film to the manufacturer.

    Sources Ilford Photo (Harman Technology), Statement on 120 roll film (2 March 2020); Ilford Photo (Harman Technology), Updated 120 roll film statement (14 March 2022); Ilford Photo (Harman Technology), FAQs: Advice for airport X-ray scanners: film and papers; storage

  2. 02

    Light reaching the film through the red window

    Occasional
    How to tell
    A fog patch or streak behind the window position rather than a copy of the backing-paper print, on cameras with a red window.
    Test it
    Check whether the window was uncovered in bright light, and whether the mark sits at the same place on each frame.
    The fix
    Keep the window covered except while winding.

    Source camera-wiki.org, Red window

Avoiding it next time

  • Store 120 film cool and dry.
  • Process exposed 120 film soon after shooting.
  • Be wary of expired or second-hand 120 film.

Go deeper