How to spool a reel
Spooling is done once a season and paid for all season. Twisted line throws loops on every cast, and no amount of winding will fix it afterwards: it has to come off and go back on again.
Where twist comes from
On a spinning reel the spool is fixed and the line is laid around it by the bail arm and its roller. Every turn of the bail adds one turn to the line about its own axis — that is built into the design and is not going anywhere.
But that turn can either add to the way the line leaves the filler spool or subtract from it. So what decides is not the reel but how the filler spool lies while you wind.
How the filler spool should lie
Lay it flat on the floor — label up or label down, and it is not all the same. Line comes off it in coils, and the direction of those coils has to match the direction in which the bail lays them on. There is no need to guess: it takes a minute to check.
The check that takes a minute
Wind on twenty or thirty turns, put the rod down and slacken the line between the first guide and the reel. If it gathers into coils and kinks, turn the filler spool over. If it falls in a loose curve, you have it right.
Run the same check after the spool is full: pull off a few metres and let go. Straight line hangs in a curve, twisted line rolls itself into a spiral.
Tension while winding
Wind the line on under tension, otherwise the lower turns lie loose and the upper ones bury themselves between them under load — and the spool jams on the cast. The simplest way is to run the line through a cloth held in your fist.
The tension should be even rather than heavy: what matters is not the force but that it does not change from start to finish. Uneven winding leaves ridges, and a ridge throws a loop on exactly the longest cast.
How much to wind on
Up to the spool lip, but not level with it — a couple of millimetres should remain. An underfilled spool costs you distance: the line catches the lip as it leaves. An overfilled one sheds turns by itself while the reel simply lies there.
On a baitcasting reel leave more room: the spool revolves there, and spare turns near the lip are a backlash waiting to happen.
Backing: when there is less braid than room
Braid is often bought in shorter lengths than the spool holds — there is no point in filling its whole depth with it. The empty space is filled from below: cheap monofilament goes on first, the braid is tied to it and wound up to the lip.
The join has to be flat, otherwise it will disturb the turns above it: this calls for line-to-line knots rather than hook knots. Backing also stops the whole lot from slipping — braided line is slick and will turn on a bare spool under load, taking the entire winding with it.