Dipsy lbs test line

[Jacob]

For your Dipsy leader, which mono or fluoro test weight do you prefer, with paddle or spoon?

[whaler1]

I run 20lb fluorocarbon leaders. 

[finsntins]

15lb fluoro for shallow browns 

20lb fluoro for deep water browns and kings spoons 

40 or 50lb fluoro for paddles 

[Shattered]

Ditto to what Finsntins said except I use 50lb mono leaders from diver to paddle. 

[BRsnow]

20lb spoons, 30lb flashers

[Nameless Fish]

30lb flouro for Kings on wire divers
20lb flouro for browns/early kings on braid divers

[Sk8man]

Jacob - As you can see from these answers there is no single "correct" answer to the question; each of these answers apparently works for each of the people suggesting them. A few basic things to consider and perhaps help you to decide for your situation are these: 

1.  Are you just fishing the Great Lakes and/or other bodies of water? Fishing in other smaller lakes you can usually get away with lighter leaders where King salmon aren't present. If fishing both possibly select according to where you fish the most often in terms of pound test. 

2. Monofilament and fluorocarbon have different characteristics which can suggest your selection. Mono has some stretch to it while fluoro doesn't have much - if any. Where this becomes important is in potential snap- offs under tension. I use both for different reasons. In shallow water where running smaller dipseys with spoons I run a little lighter diameter fluoro and run the drag on my reels lighter. When fishing deeper  with attractors (e.g. flashers spin doctors or dodgers) I go to heavier mono or fluoro because of increased tension on the line and rod, and the reel tension is set higher and using wire main line there is no give or stretch. I mostly use 40-50 lb test mono on my hand tied flies because this is where savage strikes from Kings can occur. Some folks use snubbers with their divers but if a mono leader is used it is unnecessary because the mono provides some stretch. Fluoro leaders not so much. Fishing down deep the "stealth" factor ascribed to fluoro is probably irrelevant too..

3. If you are using high quality reels with smooth drags with a good strength range you can often get away with lighter fluoro or mono too.

4. all the above options already mentioned will work just select for your own preference and the fishing conditions.