I find #12 lb. FC line to be a bit of a "tweener" FC line size you would probably consider for using on a bait cast reel for cranking , jerk baits (soft & hard) , a small 3/8th oz. football jig , used with a 5" Senko wacky or T-Rigged and as a light weight T-Rig with / without a small bullet weight for Trick Worms or Craws  ... Additionally most of the above applications could be used either  with straight #12 lb. FC main line or with braid main line plus with #12 lb. FCline as a leader  line . *What are your favorite applications using #12 lb. FC line for bass ?

I use it for everything. It has become my sweet spot for the perfect # test line for FC as it gives me the best cast ability for my favorite techniques wacky, T-rig(weighted and weightless), spinners/buzzbaits, etc. I will use 15# in its place if I cannot find it in 12# which isnt very often, but it does work just as well. Anything over 15# and anything less than 12# gives me issues. I’ve only been bass fishing the last couple of years though so others will chime in with more experience. 
 

edit: braid is top water only for me in 40-50#.

-This is the list of everything I use with 12 lb FC:

 

-And here is the list of everything I fish with other FC lb tests:

 

Weighted soft plastics.

It is my crankbait line, have always used it specifically for that. Fairly strong and thin enough to get the lure down to the desired depth. 

 

I also use it for light Texas-Rigging and when fishing flukes/tubes. Occasionally use as a leader if fishing braid/wacky rigs for largemouth... probably a tad thick for smallmouth in clear water.

1 hour ago, BassWhole! said:

-This is the list of everything I use with 12 lb FC:

 

-And here is the list of everything I fish with other FC lb tests:

 

Solid post. Would read again. 

Have 12lb fc on my crankbait rods and no others.

Crankbaits and jerkbaits for the most part.

 

I might use it for light pitching or senkos but I prefer 15 lb.  I use 15 lb FC probably 80% of the time when using fluorocarbon.  

Crankbaits, jerkbaits, poppers.....

Texas rigged soft plastics. That’s it. 

Cranks, jerks and open water chatter baits on bait casters. 

I also have it on 1 spinning outfit that only get’s used by the kids. 
 

 

 

 

 

Mike

Texas rigged soft plastic, jekbaits.and light jigs

As my leader on a Carolina rig.

I use 11# fluoro to rope cattle and pull 19 wheelers from the depths. 12# seems excessive. 

Cranks , Jerks , Wacky or T-Rigged Soft Plastics , Chatterbaits and Spinner Baits in open water would indicate it would not be a bad size FC line to use with at least one bait caster .