Thomastik Infeld-Blau violin strings. State of the art synthetic core strings with perfectly matched tensions enable costumization of sound covering the entire tonal spectrum. Using Infeld violin strings, players can achieve tonal preferences in a single string brand without the headaches of uneven tensions. The Infeld-Blau strings reinforce the brightness of the sound. The Infeld-Rot strings reinforce the darkness of your violin's strings.