In general, the materials used for academic dress are heavily influenced by the climate where the academic institution is located, or the climate where the graduate will usually be wearing the costume (as a faculty member at another institution, for example). In either case, the American Council of Education (ACE) allows for the comfort of the wearer, and concedes that lighter materials be used in tropical climates, and heavier materials elsewhere. In addition, it acknowledges cotton poplin, broadcloth, rayon, or silk as appropriate.