This is about some the different types of cordage available. In the first photo are several different varieties both synthetic fibers and natural. Top left row, 1 & 2, is military boot laces. These are made of heavy duty synthetic, probably nylon. These work great for a fire drill bow. These are usually 3 to 4 feet long. They come in handy for other chores too. Left row #3 is a braided nylon cord about 3 feet long. Its good for some minor chores and I believe it came off of one of those 5 in 1 survival whistles. Its cheaply made just like the whistle. You wouldn't believe how many broken pieces of these things I've found around camp sites. Left row #4 is a roll of artificial sinew. I love this stuff! Its great for sewing leather, already comes with a wax coating. A lot of the artsy fartsy types use this for Indian style jewelry and to make primitive tools. Its strong stuff, made from nylon.
Right row #1 is a band of black dyed cotton. It was tied around a blanket and thrown away after you opened the blanket. Its about 4 feet long. The white band beneath it is the same story. Seems a bit wasteful. Of course, being the consummate pack rat, I didn't let these get away. Next is a bundle of braided nylon rope I've used for a clothes line in camp for years. Its braided nylon shell with a nylon fiber center. Very strong stuff. The last item at the bottom is a roll of masons line. Its very strong nylon. I use this to make nets, I used to find it in red and blue, also.
Below is a photo of paracord. The real deal. I love this stuff, too. I carry about 200 feet in my survival bag. I've taken the center strands out and used them for fishing line, sewing heavy fabric, netting, and myriad other bushcrafty uses. The braided shell is useful too. I consider it too valuable to use for everyday type cordage. Theres cheaper stuff that fills the bill. Its just too valuable to waste.
This next photo shows a variety of paracord wanna be's. Its good for clothes line, shelter construction, and any use where a paracord type cordage is called for. Top is a big bundle I paid $1.00 for at a sporting goods outlet. Next is a hank of similar quality except its black. I use this piece for my "bear bag", a canvas sack that I put all my food in when camping in the Sierra Nevada's. I toss one end over a branch about 10 to 15 feet up and hoist the bag out of reach. Simple and it works. At the bottom is a hank still in its original package. I found this at a thrift store in the 25 cent bin. All of it is good general purpose cordage.
Here's a shot of the big bundle by itself. Notice how it looks like the real deal with that nice braided shell exterior. A lot of unscrupulous dealers try to pass this stuff off for the more expensive original product. Buyer beware!
This is a closeup of the inner strands unsheathed and unfurled. Definitely not real 7 strand paracord.
All of these are useful for different jobs. You cant beat the sturdiness and durability of man made fiber cordage. There's going to be a lot of man made material around for a long, long time after any type of collapse or severe disaster. If such a thing happens I believe people will treat stuff that can no longer be manufactured with a lot more respect and take good care of it.
Another thing I carry in my trunk bag is a pair of fencing pliers. I use these to work with wire I find out in the wilds. I was told there's still a lot of old telegraph wire hanging around in the mountains from the days of heavy logging. Its very tough steel wire and its still usable. Some of the old mine sites have lots of good wire and cable laying around rusting. Useful stuff in an emergency.