Gibson Acoustic MB13 Masterbuilt Premium Phosphor Bronze Medium 13-56 - set of strings

The high-end acoustic guitar strings GIBSON Masterbuilt Premium Phosphor Bronze SAG-MB13 are particularly suitable for Gibson instruments, but will suit many other brands.
Their design and manufacturing helps preserve the natural characteristics and expressiveness of your guitar. Each package is vacuum-packed to ensure optimal quality even during long-term storage.

Phosphor bronze is a copper alloy containing 3.5 to 10% tin and up to 1% phosphorus, resistant to various tensile stresses, wear or corrosion. It has a more powerful and bright sound than other metals, an important parameter for acoustic guitarists who play unamplified.
With the same tension as another type of material (Bronze for example), the greater density of Phosphor Bronze will leave a feeling of greater rigidity.

For your information, know that Gibson invented metal guitar strings in 1927, and introduced Phosphor Bronze alloy strings for acoustic guitars in 1932.