Variations in BP and RP spectra of main-sequence stars with effective temperature. The background colour-coding follows the effective temperature scale provided by ESP-UCD, GSP-Phot, and ESP-HS (also indicating their optimal T_eff performance regimes from our validation). We highlighted some spectra for reference and labelled some spectral features. We normalised the spectra to their integrated flux after correcting the BP/RP for the instrument response (see Montegriffo et al. 2023). We further stretched and vertically shifted the resulting normalised flux (F^norm.). We restricted our selection to comparable dwarfs: GSP-Phot stars with 4 ≤ log g,< 4.5 dex, A₀ < 0.2 mag and −0.1 ≤ [Fe/H] ≤ +0.1 dex, and ESP-HS stars with 4 ≤ log g,< 4.5 dex, A₀ < 0.2 mag (see the discussion in Sect. 2.4).