Comments about Samson Samson Solid Braid Polyester Utility Cord:
All the outdoor stores, and most of the farm stores, carry braided nylon cord. Braided polyethylene is better and not that much more expensive.
I am not sure of the nomenclature, but the smooth braided (sometimes called solid braided?), with the core, is best for tarp rigging, food hanging, etc., because it is often being pulled around tree trunks and limbs in the tensioning process.
The relative lack of stretch also facilitates this process. And the lower absorption means less (water) weight in the backpack.
I doubt if there is much of a difference between nylon and polyethylene in terms of ease of unknotting.