DD cup sizes occur naturally, and quite frequently, although not quite as frequently on the thin model types as most would like. FFF cup sizes (see above) are completely unnatural. As for medieval/fantasy scenes -- I dont think that breast implants were invented as far back as the middle ages. I may be wrong though...:) Ah well, to each their own. I'm not shooting anyone down, just trying to persuade people to use more realistic proportions. Maybe its just me, but I think gargantuan breasts look hideous. But everyone has their own artistic license and if you want to make breasts the size of pumpkins then go for it.