Black Diamond Guitar Strings Black Diamond, vintage, bluegrass, rock, banjo strings, resonator strings, dobro strings, mandolin strings, fiddle strings, violin strings, upright bass, doghouse bass, electric guitar strings, acoustic guitar strings, bass guitar strings, electric bass strings, classical guitar strings, ukulele, black strings, National Picks, metal fingerpicks, thumbpicks Black Diamond Guitar Strings and National Picks manufactures electric, acoustic, bass and other fretted strings and accessories like picks, straps