Many of the jigs I use on my table saw and band saw have a
runner that slides in the miter gauge slot. Typically, these runners are made
of hardwood. But recently I started using another type of material I like even
better — plastic.
The nice thing about a plastic
runner (like the one shown in the upper photo) is it won't swell or shrink with
changes in humidity, so it will always slide smoothly without binding or slop.
Plus, plastic is readily available. As you can see
in the bottom photo, I simply cut a narrow strip from a plastic cutting board.