[ALR-bishop]

One of my favorite sets is my Topps 68 3D set. it was a test set with very limited distribution and, I assume due to production costs, not a product Topps repeated again until 2011 with their Lineage product, and again in a small way in terms of # of cards. But I really liked that issue as well

In the 80s Topps did put out 2 "3D sets", but they were just clunky plastics.