Which Thomastik string should I buy for my viola or cello?

For a viola G replacement, the Thomastik Spirocore Viola G String listed here is chrome wound, 4/4 size and light tension. Check that those details match your instrument and current setup before ordering.

For cello, the Dominant Cello D String is a 4/4-size, medium-tension option. The Dominant Pro Cello C String is also listed as 4/4, but its tension isn’t specified in the supplied details—check that before buying if you need a particular tension.

The practical starting point is the string you actually need, rather than the range name. These listings alone don’t establish differences in tone, feel or lifespan; if you’re changing tension or trying a different setup, ask your teacher or repairer for guidance.