Don't use plastic fishing line or plastic for that matter. Heavy winds can cause it to slice or tear your vines. Also, birds can entangle themselves.

I'm building a cuke trellis (wood frame) and just bought a roll of green-colored, dual-weave nylon twine at the dollar store for $1.50 (300 ft). Check out the dollar stores for twine.

Check out this guy's twine trellis add-on

Thanks for the twine idea which I will use, also got some ideas watching youtube have to check which will be cheaper whether using PVC or wood for the frame

Thanks

I have been using heavy posts and wire for my two rows of tomatoes for the last four years.

I used a fairly heavy metal posts about 10 to 12 feet long. Squarish green three sided stuff used for attaching electrical boxes to it, found at the big box store. Put the end into a 5 gallon bucket of wet concrete and planted it. Ran plastic coated wire between the posts (25 feet apart). Added wire strands as the tomatoes grew during the season. Not real cheap, but wood posts just didn't last.

The tomatoes are attached to the horizontal wire with pieces of hosiery because it stretches and dries quickly.

FWIW, I have found a good source for small quantities of high quality ropes and lines. Llast year I supported a net trellis with some 1/4" Dacron line, and it did well. I have no connection with this guy, but I have bought many items from him and they all appear to be good quality.

Obviously you don't need technical mountain climbing rope to support a bean vine, but this site has everything from twine to anchor lines.

Here is a link that might be useful: rope guy