Spectral time series of SN 2018ec. The spectra have been redshift corrected to rest frame. The spectra have been corrected for both Galactic A_V = 0.334 mag and estimated host galaxy extinction of A_V = 2.1 mag. The epochs are provided respective to the estimated light curve maximum. The main narrow-line emission features arising from an incomplete host galaxy subtraction are in grey. The most prominent identified spectral features are labelled coming either from the SN (red) or from the host galaxy (blue). The Doppler shifted position of the SN lines are indicated with cyan vertical lines in selected epochs as suggested by the velocity of the Na I absorption minimum. The main telluric bands are indicated with a circled plus sign (⊕). For comparison selected spectra of normal Type Ic SN 2007gr are overlaid (green). The continua of the optical spectra of SN 2018ec are likely contaminated by the complex host background that was not successfully completely subtracted. Therefore, the optical SN features of SN 2018ec above and below the continuum level appear less prominent than those of SN 2007gr. The spectra have been shifted vertically for clarity.