In order to spread the chemistry between the negative and positive part of the photo, the picture goes through the rollers. If you see horizontal bars or stripes across your photo, this means that the camera’s rollers are depositing dirt or developer paste on the image and need to be cleaned.
To clean the rollers, first open the film door and remove the film pack from the camera. Then gently wipe down the rollers with a soft, damp cloth. We recommend you to check the rollers of your camera after each pack of film used.