When you talk about cordage, if you are like most folks, you talk about military type 550 cord, aka paracord. Paracord has some great properties... it's very strong, you can get it most anywhere that sells gear, surplus, camping supplies, etc... You can make some really cool things out of it. It's available in a myriad of colors. You can strip out the seven inner cords for fishing line, sutures, or other needs.
It has a couple of shortcomings as well. It tangles easily. It stretches. It's bulky. But it's some good stuff.
I've recently learned of another great cordage material. Not necessarily a replacement, but surely an addition. That is Bank Line. Some folks call it Mariner's Tarred Line. It's a three-ply nylon twine, that is waxed or tarred for longevity. It can be used as is for about 165# test, separated into the three plies for 55# test, or doubled or tripled up for additional strength. It can be used for snares, trot lines, lashing, nets, sewing or repairing gear, bow drills, or any number of other uses. It takes up much less space than an equal length of paracord, and if you drop a 250' spool in your pack, you can use a cork or duct tape to use the spool cylinder for an additional storage container, perhaps some fishing hooks or something else small.
I've been wanting to build a snare trap in the front yard for a skunk we've been seeing out there, so I figured I'd run up to the local Bass Pro Shop and pick up a spool. They have it on their website. Well, the folks in the fishing department had never heard of it, and didn't seem too interested in looking for it. That's ok, I went about a mile away to Green Top Sporting Goods, a local fishing and guns landmark that is known for great customer service, and knowledgeable staff. Turns out they had never heard of it either, but at least they had the interest to ask around the store to other staff.
So, I came on home and looked around on line. Wouldn't you know it, I found it easy. My buddy Mitch, up at Native Survival has it in stock. A 250' spool for only $12, including shipping. I've placed my order, and as soon as it comes in, I'll make my snare and put up some pictures. I think Mitch is teaching a primitive wilderness survival class this weekend, so I'm looking forward to getting my bank line after he gets back in from the field.