The National Greentown Glass Association, Inc. is a non-profit organization dedicated to the promotion of Greentown Glass preservation and collecting. The NGGA is active in disseminating specific knowledge concerning Greentown Glass and promoting education and research on the history and products of the Indiana Tumbler and Goblet Company, which operated in Greentown, Indiana from 1894 to June 13, 1903.
Every February, May, August and November, the NGGA publishes a newsletter containing articles, news and features of interest to Greentown Glass enthusiasts.
In early June, the NGGA holds its annual business meeting and dinner program in conjunction with the annual Greentown Glass Auction.
Greentown Glass collectors from all over the USA and Canada converge on the small town of Greentown, Indiana to participate in the annual convention, auction, antique show, business meeting, educational programs and fellowship with fellow collectors.