Backer line question

I saw Swindle video the other day that shows it puts several yards of line on his reel then ties his main line to this line when he is changing line. What is the purpose of this line back as he called it I think. First time I have seen or heard of this.

It can provide at least 2 advantages.

If using backing for Flouro or Mono line it can save you from spooling a say 150 yards of good line each time.

If using it for backing with Braided Line it will provide a slip resistant start for the very slick braid.

If you don't start the spool with Mono of Flouro with Braid you would need to wrap some Electrical Tape or such around the spool before tying the Braid to it.

This...

It saves you money and time as well. You can strip a reel to your backing and re-tie in less time than stripping the reel back to the spool.

6 or 7 years ago when I saw that Aaron martens tied braid backing on his reels for fluoro/mono I went through my reels and added braid backing to every single one. And I gotta say I think it made them perform better. Plus I always ended up tying a much stronger knot to attach my main line to the backing. But I've grown too lazy to continue the trend and will just leave a couple of yards of whatever I previously spooled up on the reel before re-spooling.

why braid for backing? like it says above braid slips if you don't put electrical tape down or back with mono first. The main reason is to save $$$, fluoro is expensive, I back with Trilene big game.

I use cheap braid and a tab of painters tape!

Never had the so called slipping problem I hear about with braid and I’ve been stringing braid for saltwater reels way longer than I’ve been bass fishing.