ðə ɹɪˈækʃən bᵻtwˌiːn ðə tˈænɪnz fɹʌmðə ɡˈɔːl nˈʌt ænd ðɪ ˈaɪɚn pɹədˈuːsᵻz ɐ kˈɑːmplɛks ðæt ɡˈɪvz ðɪ ˈaɪɚn ɡˈɔːl ˈɪŋk ɪts kˈʌlɚ.
The reaction between the tannins from the gall nut and the iron produces a complex that gives the iron gall ink its color.