String packets advertise one number — the thinnest string's diameter in thousandths of an inch — and guitarists argue about it endlessly. "Nines" versus "tens" is really an argument about tension: a thicker string must be pulled harder to reach the same pitch, and that extra pull changes how the instrument feels under every finger and how it drives the pickup or top.
The trade, honestly
Lighter sets (9s on electric, 11s on acoustic) bend easily, fret with less effort, and forgive a returning or beginning hand — at the cost of a slightly thinner voice and easier accidental pitch-bending. Heavier sets (10s, 11s, 12s and up) hold tuning under a hard strum, feed the pickups and soundboards more energy, and suit riff and slide playing — at the cost of real extra finger work, especially on barre shapes. Neither is more serious; they are different specs for different hands. When in doubt: 9s or 10s electric, 12s acoustic, and revisit once your calluses have opinions.
Change day
Strings die gradually — corrosion and finger grime damp the high frequencies first — so the decay hides from you day by day. The signs: they look grey, they feel rough at the frets, intonation drifts (fretted octaves against the tuner tell the truth), and the new-string zing is a memory. A fresh set is the cheapest dramatic upgrade in guitar, and changing them also swaps a subtle skill drill: one string at a time, keep the bridge loaded, stretch each string gently as you bring it to pitch.
The rest of the family
Every instrument on this site has its own string logic — derived from the registry, one row per family member:
| Instrument | Strings | Tuning |
|---|---|---|
| Guitar (6-String) | 6 | EADGBE |
| Guitar (7-String) | 7 | BEADGBE |
| Guitar (8-String) | 8 | F#BEADGBE |
| Tenor Guitar | 4 | CGDA |
| Resonator Guitar | 6 | GBDGBD |
| 12-String Guitar | 6 | EADGBE |
| Terz Guitar | 6 | GCFA#DG |
| Loog | 3 | GBE |
| Jacob Collier 5-String | 5 | DAEAD |
| Vihuela | 5 | ADGBE |
| Guitarrón | 6 | ADGCEA |
The practical headlines: the 12-string wants lighter gauges than instinct suggests (double the strings, nearly double the total pull on the neck — light sets are structural kindness). The tenor's four fifths-tuned strings span a wider pitch range per string, so its sets are their own species — never guitar leftovers. And the resonator runs heavy strings at high action on purpose: the extra tension drives the cone, and slide playing never asks the left hand to press hard anyway.