String choice significantly affects tone, playability, and durability in folk instruments. Historically, gut strings were used, but modern materials like phosphor bronze, nickel, and fluorocarbon provide stability and rich tone. Leading brands include D’Addario (EXP Mandolin), Elixir (Banjo Strings), Aquila (Nylgut Ukulele), and Martin (Authentic Acoustic). Different gauges and coatings cater to various playing styles, ensuring vibrant tones for strumming, fingerpicking, and fast melodic runs.