The markedness constraints of classic Optimality Theory assign violation-marks to output candidates without reference to the input or to other candidates. This paper explores an alternative conception of markedness that is comparative: markedness constraints compare the candidate under evaluation with another candidate, the most faithful one. Comparative constraints distinguish two situations: the candidate under evaluation contains an instance of a marked structure that is also present in the fully-faithful candidate; or the candidate under evaluation contains an instance of a marked structure that is not present in the fully faithful candidate. The empirical consequences of comparative markedness are explored, including grandfather effects (i.e., blocking by emergent markedness constraints), derived environment effects, non-iterating processes, coalescence paradoxes, and counterfeeding opacity. Theoretical questions concerning harmonic ascent and other topics will also be discussed. Comparative markedness is found to have some advantages and some disadvantages in comparison with classic OT and alternatives like local conjunction, stratal OT, sympathy, and targeted constraints.