What line do you use for large swimbaits. I have not used them and purchased my first one recently and not sure what line to use.

Eight inch glide bait 25lb premium mono.

I most use 65# Maxcuatro, sometimes with a 25# or 30# copolymer leader up to 12' tied with a blood knot. Traditional 65# braid works as well, just is a little thicker and may catch the wind more or deter maintaining depth. I'm not against straight premium mono/copolymer either. My #1 advice is to fish slow, then fish it even slower. Advice #2: If you get a follow, you can try a different lure, but don't throw the same one over and over - you'll just educate the fish to shy away from the lure. Leave and come back later.

50# Braid to 6ft 20# Pline CXX leader.
Can’t break 20# CXX

That CXX is some tough stuff. It does extremely well fishing around Galveston as a main line for me also.

What are you calling a big bait? 4oz? 10oz? How big?

20lb pline tactical. I'm throwing bullshooters and golden instigator and pizz glides. DO NOT USE STRAIGHT BRAID only time I would use straight braid is if throwing weedless baits in grass. Glides and bullshad along with other big hard baits will snap your line and you'll watch that 70$+ bait fly off into the lake.

I don't really follow TacticalBassin, but they've been doing it for a long time. For the 8" glides, they're using 80 lb Suffix 832, with a 30 lb Maxima Ultrageen leader. For the 7" and below they're using 65 lb MaxCuatro braid, with a 20 lb Maxima Ultragreen leader. For a long time it seemed that people were shying awasy from braid for swimbaits. For me, the mono or flouro leader is essential when using braid. A Hudd will snap direct braid easy.

Maxima Ultragreen is good, but I've been spoiled by CXX.
20 pound Ultragreen went on clearance at BassPro last year, so I bought a huge spool.
Third time out with it, it broke about a foot up from my line to lure knot. This was the first time in a long time that I had broken off 20# line.
It is good line, but doesn't have the abrasion resistance of CXX. I had noticed some wear on the line prior to breaking off, but I had developed some bad habits with CXX's amazing durability.

It does sink better than CXX, so you'll get more depth on your glide baits.
It also looks less visible in the water.

The 3:16 lures that are about 8".

I've been throwing swimbaits with braid to leader for more than 20 years. The key is to find a connection knot that you tie well and have confidence in...for me it's been an improved Albright but there are multiple other excellent choices. My leader material/strength is dictated by the size/type of my bait and the depth I'm fishing. My latest favorite braid is Maxicuatro in 65 lb but again, there are other great choices. Depending on water clarity I have used straight braid and I have casted off two baits in two decades...both were pilot error. I can't imagine it being easy to do. If I was only going to use one leader material it would be shock leader from the salty world of fishing. The stretch component definitely makes a difference when large fish hammer the bait next to the boat.

Not that mono works any better than fluoro the last thing you want to see is your bait still flying after the spool stops spinning. Especially if your one of those guys that will buy the expensive baits. I think most use mono due to the uncertainty that the fluoro knot they are using will hold up. I threw 7" Smash-Tech weedless down in Mexico for 4 days on 17lb fluoro using a Jam Knot and never had any issues. Now those are not super heavy baits but they are not light either. I don't really throw the hard baits but my decision would probably be based on how expensive the bait is. I am confident in my knots but spending a lot on a bait and then reading about fluoro knot failure can get in your head. Lucky for me I will never know.

This a good video about swimbaits, set up and line.

The best line size for big swimbaits is largely determined by the weight of the lure itself. With a 7-8" soft plastic hollow body swimbait you can get away with using fresh line as light as 17lb but for most large sized swimbaits I prefer to use at least 20-25lb fluorocarbon. A large swimbait will attract large bass so you want to have strong line not only for the sake of preventing the lure from breaking free during your cast but also to handle reeling in bass over 5-6lbs, sometimes quite quickly around heavy cover. Remember to read the line diameter on different brands of line as they can vary for example Berkley Trilene 100% Fluorocarbon line that says 20lb actually has the diameter closer to 25lb lines of other brands. I'll typically use 25lb fluorocarbon for heavy swimbaits like the Deps Slide Swimmer 250s or when casting an umbrella rig with swimbaits that have heavier heads made for a fast retrieve or for fishing offshore in deeper water. I hope this helps!

20 lb. Big Game.