What the manufacturer says:

• Obligato strings have a core made from a modern synthetic multifilament fibre.
• Obligato strings sound warm and full, yet have a brilliant and focused tone.
  
• big and powerful tone
• excellent playability and response throughout the entire dynamic range
• excellent tuning stability
• absolutely insensitive to variations in temperature and humidity

Violinmaker’s recommendation:

“The ‘Obligato’ viola string is a very beautiful, warm yet powerful sounding string for the intermediate and professional player. Great response, great tuning stability. I only recommend to use the whole set. ”