Given the relevance of line strength gradients to study the formation and secular evolution of elliptical galaxies, we propose to measure deep line strength maps of nearby ellipticals with OSIRIS on the GTC. The methods of observing and interpreting these maps are guided and optimized on the basis of highly specialized and sophisticated synthesis models and will be used to derive relevant parameters of the integrated population, such as stellar metallicities, ages, abundance ratios, and the initial mass function. Our main goal is to provide further and stronger constraints on the formation and evolution scenarios of elliptical galaxies on the basis of the information provided by the global and radial distribution of their stellar populations.