These strings have nylon core, which is flatwound with nylon on the G and D strings, and with monel on the A and E strings. The strings have a comfortable soft feel, with a lighter tension than most steel strings, and good tone and volume.
I play Bluegrass, Jazz and Country-Blues. They are flexible and durable enough for comfortable slapping, but because of the different materials they sounds completely different from each other. The top strings have kind of a "tan" color to the wrapping, so they almost appear to be gut strings from a distance. They have a light feel but still have a warm tone. You might consider this set to be a alternative to gut strings if you want some of that flavor -- but with more definition and longer sustain than real gut. Furthermore the strings sounds brilliant for a long time and need no care!
All things considered great strings for the doghouse!