Phosphor Bronze Acoustic Strings for 12 string 10-47 3-Pak BlackSmith acoustic guitar strings are made from the finest materials and manufactured using the latest automatic servo-controlled winding machines. US-made phosphor bronze and steel make for a long-lasting string with increased sustain and a cleaner, warmer tone. Our proprietary computer-controlled winding technology creates strings with a very constant winding surface and even tension, resulting in stable tuning, accurate intonation and outstanding playability. Sub-Zero treated smooth steel strings offer a brilliant tone with a silky feel. With BlackSmith acoustic guitar strings you will experience the perfect balance of consistency, sound and playability. Vacuum sealed in patented anti-kink packaging prevents oxidation and damage to the line. PB12-1047 - BlackSmith's most popular 12-string phosphor bronze acoustic set, ideal for players who prefer a warmer tone with high-end sheen and more projection. Optimized gauge for balanced string volume and comfortable playability.