What is the proccess of making a flexable seem on a plastic sheet?

I am trying to fugure out how to create a flexable seem out of a sheet of plastic. For example if you had a 12';x12'; sheet of plastic 1/16'; thick and you wanted to fold it in half to create two 6';x12'; flaps. How would you create a seem at the fold that could be easly folded and unfolded repeatedly for a long duration?What is the proccess of making a flexable seem on a plastic sheet?
You could do this with a ';living hinge.'; Co-extrude the plastic profile with rigid plastic connected with the flexible plastic living hinge. Long duration needs to defined.