The guitar strings our guitars ship with are these: Daddario resonator flat tops
But we buy 15/s as singles and replace that for the top end. Use bigger strings and tune down. Let’s things vibrate. Use flat tops on all your guitars – a little bit warmer, no string noise Once you use flat tops the squeaks from non flat tops will irritate the daylights out of you.
We’ve put some nickel flat wounds on by request – quieter, but really warm and fun.