I use strips of vinyl baseboard molding from the lumber yard under felt I cut. Cheap, long, and won't dull blades. I've also built a felt-piece chopper that works vastly better than anything commercially available. I can cut a whole set of anything in about 5 minutes, with accuracy to about a thousandth of an inch. I'm discussing marketing them through PianoForte Supply. Euphonious Thumpe !
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