It isn't just about flexibility; it's about bending the note till it rings true.
Martin SP Flexible Core strings have a thin but strong core wire and a thicker wrap wire which allows them to be flexible and easy on the fingers while holding standard tension. SP Flexible Core strings feel soft to the touch, making them ideal for beginners. But don't be fooled by comfort! Just ask Tommy Emmanuel who performs with Martin's SP Flexible Core strings night after night. With SP Flexible Core, you get total flexibility and total control.
Martin & Co. designs and manufactures the strings themselves. Like their guitars, each string is made with patience, care, and precision with only the highest quality materials producing strings with exacting tone and superior performance. Not only are their packaging materials minimized and 100% recyclable, but the envelopes reduce the tarnishing effect on the strings.