Design aesthetics concerns the study of the way the features of a product are perceived by an observer. This paper shows that the moment of perception can be advantageously described with the help of results from affective neuroscience. It also shows, among other things, that the affective state of an individual is always prior to a later, slower, conscious cognition, and that it influences judgment during purchase and use. This can also be observed in great detail through the measurement techniques used in affective neuroscience. A comparison with current models of affect in design research is also presented. Finally, results from affective neuroscience allow the designer to play with emotions, knowing which stimuli will have an impact on the individual and when.