Maria, I have tried various types of fishing line for various types of fences and barriers.
Each of them resulted in frustration for me, as I found myself more deterred than any wildlife, dangerous that I found myself to be running at time walking into it. When one reaches by reflex for a bumped stretched fishing line this can result in minor sometimes painful cuts.
If repelling deer and other wild critters is your intent than a method Geoff Lawton made a two minute video about might be worth your time if practical. I will post the link below. If finding parts is a matter of need, Bartering with old farmers and fence post friends is ideal. The method in the video is memorable, and non lethal learning experience for most any wild animal. good luck. Larry