A new library of optical spectral models for analysis of populations of stars, allowing for different population ages, metallicities and [alpha/Fe] element abundance ratios. The models are built from empirical star spectra modified by theoretical star spectra, which are then combined via an initial stellar mass function and weighted by isochrones to produce integrated light spectra of single age, single metallicity, single [alpha/Fe] abundance pattern populations called SSPs. A full description is published in Knowles et al. 2023, Monthly Notices of the Royal Astronomical Society, Volume 523, pp3450-3470.