I know what backing is but I want to know what the point of it is. Like say I have 30 yards of mono backing and 70 yards of fluoro main line. Why not just spool up 70 yards of fluoro and be done? Is there advantage or what? Thanks guys!

I don't make a habit out of casting with a spool that is only 2/3 full but I believe you will get less casting distance if you do. I say that because I backlashed real bad one day with my Curado 50E and I had to cut a bunch of line from the spool. The spool probably wasn't even half full but I remember not being able to get near the distance with the near half full spool as I was with a full spool.

Yes there is a point. You will never reach that last half or 1/3 of the spool so you're better off only using what you need. Saves yourself some cash and you can fill more reels with less spools of line.

John is right. You're better off always having a full spool to maximize casting distance.

John G has a valid point.

Each revolution of the spool releases a certain amount of line.

Revolutions with the solo full release more line than a revolution at 70%.

What I do a lot of times is spool completely with the line I prefer to use the first time. Then, when it's time to respool down the road..........I only use 70ish% . Using the original line as backer.

Well I fill my spool with my main line but I was wondering if backing has any advantages other than saving more expensive line.

Well mono backing with braid prevents line slipping on the spool as well. Some guys just tape it down on the spool.

Thanks guys.

Great way to save money.  When the sales come around I pick up the cheapest braid available and use it as backer.  $1-3/100yd backer is better than $15-20/100yd top shelf line when you are spooling 20 rods.

Really makes that $40, 200 yard spool of FC last much longer. I back all my baitcasters that have FC or braid.

Just curious - do you guys put backing on your spinning reels as well for braid/FC?

I don't use backing on my spinning reels. Larger spool means less line. But I do fill the spool more with my wavespin reels, as the design just about entirely eliminates loops and if I use nanofil line I can get great distance!