Previous studies show that producers that span category boundaries exhibit lower fit to category schemas, accumulate less expertise, and elicit negative reactions from both critics and consumers. We propose that the negative reaction to category spanning also depends on another mechanism: widespread category spanning lowers categorical contrast—the sharpness of a category’s boundaries. Lowered contrast blurs boundaries among categories due to the impairment of the comparison processes underlying evaluations and the growing disagreement about the meaning of the category. These processes lower the appeal of all products in a category and make it problematic for any offer to receive widespread acclaim. By making boundaries less salient, reduced contrast also lowers the advantages of category specialism. These propositions receive support in an analysis of style categories and ratings of Barolos and Barbarescos, elite Italian wines.