Originally Posted by jennyema
I have a glasstop stove and have cast iron pans both with and without and it makes zero difference.
Dont worry about any marks on cast iron.
Master Chef, I would say that you are absolutely correct as to the glass top cook stove. The heat rings would not make any difference at all. My thinking is that the quality of ore used back in the 1880's into the 1940's was better than the latter years. in general the cookware was thinner, and more smooth which allowed better seasoning and therefore more nonstick.