Medium Gauge (11 – 50). Developed by our Master Luthiers in the 1950s, Gibson Vintage Reissue Strings are factory specification at the Gibson Custom Shop in Nashville, TN. Made exactly as they were in the original Gibson factory in Kalamazoo, these strings are wrapped in the purest nickel for renowned feel, clarity & warmth. Vintage Reissues are the only choice for a timeless tone that captures the voice of Gibsons Golden Era.