Oliv VIOLA Set by Pirastro - The sheep gut core of the Oliv strings is manufactured, wound and polished in the traditional way, by hand. The sound is brilliant. Oliv strings offer the typical beautiful sound of gut strings. The set contains the following strings: A-aluminum 13 3/4 D-gold-aluminum 16 1/4 G-gold-silver 17 C-tungsten-silver 19 3/4.