Is nylon sheathing for DIY cables just window dressing?


Hi, quick question. Looking to make my own calbles, like the Mogami W3104 -12AWG 4 Conductor Speaker Cable material. It seems relatively easy to cut, strip cables into 2 separate right / left leads and add banana plugs. But every time I look for a little DIY u-tube education they all add the shrink wrap tubing and nylon sheathing to the assembly process. Is this really necessary? I can see where maybe using shrink wrap from the casing edge that was cut exposing the 4 individual leads and also having shrink wrap tubing over banana plugs to keep out air, but do you really need the fancy nylon sheathing? It adds about another $50-100 to the total cost. Thanks
128x128phill55
No, you don't need the fancy nylon braided sleeving, they are just cable dress up. A lot of high-end cable manufacturers use them to disguise the cable used underneath or to protect their method of construction and the material used, this is especially true when a cable is advertised as being hand-built or hand-made. The heat shrink used does provide strain relief where the connectors are terminated to the cable.
Most of my DIY cables use tinned copper braid wrap for shielding and damping.  The tinned coatings rub off on your hands unless covered by Tekflex plastic braid.  Tekflex also looks nice and is relatively cheap from MacMaster Carr on-line.  Not much money in the scheme of things. 
Thanks for everyone's responses -  The Mogami W3104 -12AWG 4 Conductor Speaker Cable is not cheap at $4-6 per linear foot, but I compared them to my Cullen cable cross over series and these are as good, with a little more tightness in the bass. And as god as the Cullen cables are, they run about $30 per linear foot. BUT, for those of you looking to use standard banana plugs (like SIlverbacks) be careful as this wire is so thick, that twisting the 4 leads into 2 will barely go into standard banana plugs - you have to use the kind with the screws that go outside of the cable housing. I should know, I had to grind down the screws on the silverback banana plugs - was a pain in the a_ _ but it worked. Overall, very impressed with the sound of these cables. 
Most of my DIY cables use tinned copper braid wrap for shielding and damping. The tinned coatings rub off on your hands unless covered by Tekflex plastic braid. 

@dgarretson The OP was asking about speaker cables, do you shield those too? :)

Best,
E

Hello Eric.  Yes, I shield the DIY speaker cables.  At the amp end I solder a pigtail to the cable's braided shield and connect the wire to earth ground.  At the speaker end of the cable, pigtails fan out from the cable shield to the metal baskets of the drivers and the ground post on a supertweeter. :})