Danish luthier Albert Augustine moved to the USA in 1926, where he develloped the nylon guitar string in cooperation with famous musician Andrés Segovia. UsingDuPont nylon, Augustine perfected the winding and polishing of the bass strings and presented the perfect alternative for catgut strings, that had been used untill then but were very hard to get. Albert Augustine Company has kept its leading position in string making ever since.These strings can be freely combined to suit your needs:blue basses (high tension)red basses (medium tension)black basses (light tension)gold basses (light tension, but brass plated)classic trebles (regular tension)imperial trebles (medium tension)regal trebles (high tension)A mix of medium and high tension makes the Regal/Red the perfect blend of power and refinement.