Pirastro Original Flexocor (dark purple winding) rope core steel strings are especially suitable for arco. Original Flexocor offers brilliant sound, while providing short sustain. They can be a very good solution for large or inherently dark-sounding orchestral basses. If your bass is neither large nor usually dark, and you prefer brilliance without excessive edge to the sound, consider Flexocor Deluxe (red/white winding), and if you prefer a warmer sound with cleaner bow changes and string crossings, look into Flexocor (just Flexocor - maroon winding).
What strings are right for your playing style and your bass? Try our INTERACTIVE BASS STRINGS CHOOSER