This paper investigates the perceptual nature of affective properties—qualities such as sadness, excitement, boredom, or comfort—that we experience as belonging to objects, environments, or events. I propose a taxonomy that distinguishes three classes of affective properties: arousal properties, expressive properties, and affective affordances, each characterized by different relations to perception, affectivity, and response dependence. Drawing on philosophical accounts of high-level perception and ecological psychology, I argue that these properties can be considered at least partly perceptual insofar as they contribute to the phenomenal character of experience. I then explore how we learn to detect and refine our sensitivity to these properties by appealing to the phenomenon of perceptual learning, focusing on mechanisms such as repeated exposure, attentional weighting, conceptual feedback, and emotional responsiveness. While the learning of arousal properties is largely shaped by affective reactions, the learning of expressive properties depends on recognizing perceptual patterns, and the learning of affective affordances relies on accurately perceiving opportunities for effective emotional interaction. I conclude that affective properties are overall amenable to perceptual expertise.