Twelve Strings Acoustic Guitar Strings. They offer a striking natural sound throughout their life. They have special coating and winding which helps to avoid corrosion and ensures constant quality of sound. Strings have brighter attack and their feeling is like traditional strings. The winding is made of phosphor bronze and gives them warm and well-balanced tone. Version: Light. Thickness: 010, 014, 023, 030, 039, 047, 010, 014, 009, 012, 018, 027.