Silk cored strings with metal windings.
2 out of 2 found the following review helpful
Pros: Powerful, and very warm sound, flexibility of play. The velvet are rich in harmonic and requires very good technique with a bow. This string are 80% of the quality of the sound of my Cello.
Cons: Currently, I have yet to find any defect.
Other: The core of natural silk provide a very good stability of tune and the diameter is thicker, it's very nice for playing the A string. Probably the best strings I tested Considering the quality, the price is quite correct.