Recent improvements in space based (uv to 1um) and ground based spectra (1 to 2.5um), together with accurate broad band stellar-type photometry enables continuous spectra of most spectral types, accurate to 2 to 1% over the spectral range.

Previous libraries cover smaller spectral ranges, or offer lower flux accuracy (<~5%) over significant portions of the range.

INGS provides standardised spectra and enables photometric comparisons over appropriate stellar types

Overall Flux accuracies of 1-2% are still limited by ground based observational inaccuracies, and reduction inconsistencies, but are significantly improved. The spectra are photometrically consistent across multiple observational approaches and uv-optical to ir wavelength ranges.