Abstract Although, as argued in Chapter 9, cognitive penetration occurs in the case of ambiguous stimuli especially when feature-based attention is deployed, cognitive penetration is not as common as many suppose. This chapter discusses the question of whether knowledge of what is depicted by a figure has an effect on whether it is seen as a figure or as ground, concluding that classic effects are more likely to be a product of familiarity, a non-cognitive form of memory and of standard gestalt principles than of knowledge. The only clear cases of cognitive penetration in figure/ground perception are effects of feature-based attention of the sort discussed in Chapter 9. Experiments are discussed that appear to show that knowledge of the color of fruits and vegetables affect how they look. The chapter argues that these effects, if they exist, are probably due to associations within the visual system. The chapter also discusses experiments that suggest the effects are not visual at all.