On Saturday I picked up a MTM shirt manufactured by Individualized Shirts, expecting it to have mother of pearl buttons. The buttons look to me like they are MOP, except that they have an opaque white back that is plastic. The shop owner looked embarassed when I asked, as he assured me the buttons would be MOP, and he didn't have answers to my questions. Are buttons made that have MOP in front, with a thin plastic backing? Is there a definitive test I can do to distinguish MOP from plastic? I've read in various threads that MOP is cooler, etc., but I really can't tell using this method. FWIW, I recently ordered a MTM blazer with MOP buttons, so I've seen MOP recently. The shirt buttons have the same shine (with alternating dark and bright shiny reflective bands), but the reflected light doesn't show the same range of colors as the MOP blazer buttons (I'll post pictures if it would help and if I can borrow a camera).