Heh Heh. I would bet you anything that if my mother was alive, she could find a difference.
Are they bread plates or salad plates? The salads are larger. Luncheon plates are just slightly smaller than dinner plates which are slightly smaller than the European dinner plates I think, they are really big. I wish I had the oversized plates but never even thought about them when I got china and none of the stuff I got from relatives has the big plates.
By the way, my new dishwasher (I had to get rid of the old one, because dry cycle was not working properly and was filling up with mold, and when the mold got to be too much (particularly when it started collecting on the dirty plates), I just had to say enought is enough), is so cool. It has two drawers, which you slide out, each separately operated. And it is so quiet. You can turn it on, and still watch television in the family room which is open to the kitchen, without much problem.