Home Features AP International Offering New Fret Butter Fretboard Cleaner from DMI Guitar Labs AP International Offering New Fret Butter Fretboard Cleaner from DMI Guitar Labs planetsixstring September 9, 2017 comments off Tweet on Twitter Share on Facebook Google+ Pinterest AP International is pleased to announce they will be offering the new Fret Butter fretboard cleaner from DMI Guitar Labs. guitar player