This chapter discusses the effects of contextual support on the incidental acquisition of vocabulary through reading. First, the research on unknown word density is reviewed, and discussion is provided on how to achieve the optimal level of known words that guarantee research participants comprehend texts without hindrance. Then, different methods for ensuring known word density are explained before being compared and contrasted. Next, a discussion of the pros and cons of how contextual richness has been operationalized in previous studies is provided. After this, the discussion focuses on the effect contextual richness can have on research participants’ ability to infer the meaning of unknown words encountered incidentally. Following this is a review of studies that have investigated the effects of enhanced salience on the incidental acquisition of vocabulary through reading. These studies have mainly looked at three methods of drawing learners’ attention to targeted vocabulary: pictures, highlighting, and glossing. These three methods are dealt with separately by reviewing what the research literature can tell us and then discussing future areas that deserve more nuanced attention. The chapter ends with a commentary on the issues revolving around contextual support.