I see there is a series of fine striations on the negative. Hmm, I will have a close look at where this may be coming from but I am suspicious it is the backing paper on the 120 film. This is Kodak TMY400 and shot with my Yashica 124G. I don't think I've seen this problem before nor since so I don't think it's the camera. It could have been the squeegee I use when drying the film I suppose but again subsequent films are clean.