I am building a jig for a router table and I realized too late that using an aluminum base for the jig will scratch the router table which is also made of aluminum. What can be used to prevent this scratching and to make the sliding smoother ?
Ultra-High Molecular Weight (UHMW) plastic is available as self-adhesive tape in various widths and thicknesses. It slides well over most smooth surfaces.
Depending on how stuff your jig is, you might not have to cover the entire bottom.
Oh -- and you probably want to ease (round over) the corners of the jig so they don't scratch, catch, or otherwise cause trouble.