The aim of this study was to use a minimum number of measured colour patches to evaluate the colour gamut of an n-colour printing process. Traditionally, the colour gamut of a printing system has been derived by printing and then measuring a gamut target for example, a profiling chart. For an n-colour printing (printing with more than four process inks), it is desirable to know the colour gamut of the given set of inks without having to print a large number of test patches. Different spectral printer models were used to predict the gamut of a 7-colour printing process. The colorant space was divided into sectors each containing four inks. For each printer model, the colour gamut of the each four-ink sector was predicted. All sector-gamuts were then combined to predict the overall colour gamut of the n-colour process. This predicted gamut was then compared with the gamut obtained by measurement using a gamut comparison index (GCI). The Yule-Nielsen modified spectral Neugebauer (YNSN) model gave the best accuracy, at the cost of a larger number of input measurements, than other models. A combination of the Kubelka-Munk (KM) and YNSN models performed well with the fewest input measurements. (c) 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 408-415, 2015