The International Sign Association (ISA) was founded in 1944 to represent manufacturers, users, and suppliers of on-premise signs and sign products. ISA exists to support, promote, and improve the $30 billion-a-year sign industry, which sustains the nation?s nearly $3 trillion-a-year retail industry. Our members' products are produced by more than 400,000 employees in all 50 states and 69 foreign countries.