Gut, synthetic and steel string cores

The core runs through the centre of a string; a winding is the material wrapped around it. A silver-wound string may have a gut, synthetic or steel core.

Read each string’s specification

D’Addario distinguishes solid steel, stranded steel, synthetic and gut cores. A set can use more than one construction, so do not apply the description of one string to the whole set. Material alone does not establish which option will suit your instrument.

Source

D’Addario: orchestral string construction chart

Choosing string size, gauge and fittings