Vai had several custom prototypes of these guitars built (which were used on the "Eat 'Em and Smile" tour) by Joe "Jem" Despagni, a custom guitar luthier and friend of Vai's. Due to Vai's highly coveted position in Roth's band, many guitar companies were eager to propose endorsement opportunities. In response to these offers, Vai sent out the specifications of the JEM guitar, detailing that the company that returned the best guitar would be given the endorsement. Dissatisfied with the guitars returned and unwilling to compromise, Vai held out on a guitar endorsement until Ibanez approached him, sending him an instrument superior to that of the other companies and willing to follow his instructions. After the pre-production prototypes were perfected, the first production Ibanez JEM 777 guitars were unveiled at the NAMM Show in 1987. Since its original 1987 release, the JEM has become one of the longest-running and most successful signature series guitars in history, with its sister guitar, the Ibanez RG, being the second highest-selling guitar (behind the Fender Stratocaster) on the market.