This is the official laminate for the Grateful Dead Spring and Summer 1990 tours. This laminate has a 3D/hologram effect that was achieved through the use of multiple layers of different foils, It was the most expensive laminate to produce (and most difficult to counterfeit). This laminate is known as "Guitar Sam".
Verification can be found here: https://www.dead.net/archives/1988/clippings/gd-laminate-front-spring-summer-1988
