Just something I considered as I went through various fasteners .. and the reason I went with the plastic/vinyl coated paper clips is the remote possibility of rust.
Yes, our home is air-conditioned....
but we also live is S.E. Texas.
In this part of the world you feel the need to breathe through gills a lot of the time! The heat & humidity is just unbearable especially this summer.
I feel that the other metal options were too much of a risk in the long run.
The solid plastic clips, at least the ones I tried broke when I tried to fasten the fabric on the small boards.
The large coated paper clips have done what I wanted for very little cost.