A few time ago I got a Holga 120 GN for a project. I kept the 6x6 mask on (cause I didnt want the extra vignetting) and for extra protection against possible scratches I covered the vertical sides (where the film basically comes in contact) with electrical tape. Moreover, for more tension on the film I put a piece of cardboard under the spool. At the first HP5+ rolls, I didnt notice any obvious scratch on them. However, a very disappointing result came out when I put a Fomapan 200 roll in the Holga. I noticed a batch of parallel smooth lines all over the film, like rubbing the film with a harsh material.The effect became quite obvious when I scanned the film. Actually, all of the images are destroyed. You can see the attached picture. After that I checked carefully the rest of the films (around 5-6) and I noticed also several continuous scratches on them. The HP5+ looks far more resistant than FP200, but many of the images have also been affected by the scratches. The problem is that I scrutinised the frame of the camera and I didnt find any hump on the plastics. I just smoothed with sandpaper the clips of the mask and covered them with tape. I will try again. I checked also some films that have been shot with another camera, but developed with the same reel. Nothing at all. I cannot think of any other cause of scratching as the film is covered over by its paper and it doesnt touch either the sponges under the spools or the back and the inner part of the camera. Any idea?