I have at some points wondered why paracord is made the way it is. So I did some research and this is what I found out!
From experience we know that paracord is made using inner strands (called a kern), which are braided, and an outer sheath (also called a mantle). Unlike the inner strands, which are twisted into their form using smaller yarns, the outer sheath is woven (often using 32 strands!).
What may or may not be surprising is that the inner strands are the ones doing the heavy lifting. Although the sheath does add to the strength of the cord, it is not meant for that purpose!
As mentioned, the inner strands are the part of the paracord designed to give it it’s strength. So, what does the outer sheath do exactly? Well, besides adding to the minimum tensile strength (the point where the cord or rope deforms or begins to break), the sheath is there to provide protection to the inner cords. As you will know from experience, the inner strands really are very delicate and can fray easily as well. Having a sheath around them makes sense. But there is a bit more to it than that. The sheath in kernmantle rope ensures that we have a single cord to work with and adds grip. This means that the outer sheath is the one that makes paracord usable as the rope! Without it, paracord would be weaker, easier to damage and harder to handle!
So the inner strands provide the strength, while the mantle provides the handling characteristics.
This is why we refer to rope made with an inner and outer sheath as kernmantle rope, which is a well known term often used when describing paracord.
I find little bits of information like this enjoyable as well as practical. Knowing why something is made the way it is makes you appreciate it. You are also able to replicate the technique if the need arises, adding to your practical skills.