I don't know much about these but I have a few and would like to offer them here before other avenues of sales. This one is a brown spot kind of glazing on a light yellow with NATIONAL INSULATOR ASSOCIATION embossed in the front. It also has a little red felt piece on the bottom and is mint. I am not sure of all the years these were made, but it was in the 70's/80's. I'm asking $5 plus shipping for this one. A little update on these commemoratives thanks to D. Dahle. This one is for the 1981 convention. Please see http://www.collectinginsulators.com/Commemoratives/Commemorative-Porcelain.html for more info.