Bank line, aka “tarred twine”, is a black polypropylene cord/twine that is similar to tennis court netting. It’s exceptionally strong, UV resistant, and inexpensive.
The name comes from trotline fishing (from the “bank” of a waterway, hence the name) for catfish or similar critters, where you toss out a strong main line baited with multiple hooks, and return hours later to check your line.
Bank line comes in a variety of diameters and strengths.
It does pretty much everything paracord can do, but in a smaller diameter, so it's a lot lighter and takes up less room.
Paracord is rated to about 550 pounds.
#36 bank line has a reported breaking strength of about 320 pounds.
#12 bank line has a breaking strength of around 100 pounds, and is accordingly thinner and even lighter.
Popular in the survivalist / bushcraft world, bank line can be immensely handy around the house, garage, shop, or campsite.
Think lashing most anything, tent or tarp guy lines, clothesline, trellis for the garden, hanging a food bag, primitive shelter construction . . .
On a big wall, everything needs a way to be clipped in. Bank cord is perfect for making small clip in loops for most anything, and is less expensive than the bulk 2 of 3 mm cord normally used.
The bank cord I got is “tarred”, which is about what it sounds like. The cord has a thin layer of sticky tar-stuff. This helps knots to be more secure It has a mild petroleum-like smell, which goes away shortly after you open the bag.
The stickiness is not annoying at all. It doesn’t come off on your fingers, just has a mild tacky feel to it.