Used set of La Bella black nylon strings. Used for about 3 months. There is no noticeable deterioration, and the sound will be slightly less resonant, as if they had been used for about 3 months after installation. If you have any questions, please feel free to comment. I can also answer questions such as "I can't imagine the sound." The following are search terms to accommodate variations in notation: Contrabass strings Wood bass strings Double bass strings Upright bass strings For jazz For pizzicato La Bella 7710N Professional Jazz Light Tension Double Bass Strings Black Nylon Tape Wound on a Rope Core