I use wooden clothes pins and metal binder clips. For 35mm and 120 I"m always clipping it to part of the leader that gets cut off anyways. If you are looking for non marking for large format negatives, I'm not too sure.
I used to use wooden cloths pins but they left sawdust/wood fiber debris... So I use the Paterson clips now for 35mm and 120/70mm and though they pierce the leader, that's cut off anyway, they don't leave streaks or drip water, are weighted, I'm a convert give them a try
Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
~Stone | "...of course, that's just my opinion. I could be wrong."~Dennis Miller
Flipped clothes pins. I also have a plastic clothes drying rack that is basically a rectangular grid with 20 something rotating clothes pins attached to it, I clip my film there and wooden pins on the bottom for weight.