I often rout tiny V-grooves in my cabinet doors that require sanding before finishing. Sanding the grooves with just sandpaper folded in half wears out the sandpaper quickly. It’s also floppy, making sanding difficult. I recently discovered that using a 6″ putty knife to back up the sandpaper provides more rigidity to sand the grooves evenly and remove unwanted ridges. The sandpaper lasts longer, and the whole sanding process goes faster, too.
– Dale Miller