The various and myriad test issues spit out by Topps have always ignited collectors' passions and, as the years pass, done a number on many a bank account, mine included. What we tend to think of as a test issue really began in 1965-66 and seems to coincide with the move of production from Brooklyn to Duryea. Yes, there were tests before this (and probably far more than anyone will ever know) but the method of distribution seems to have been refined by the mid-Sixties into what amounts to a standardized countertop display featuring a blank, white box, with white wax packs within. These came with a large, colorful sticker affixed to the front that identified the set and often used the planned graphics for the full retail release. A smaller ingredients sticker was affixed to the reverse. Not all sets were tested this way but for anything that was a standard sized card, it was pretty much the norm, although some regional tests seem to have had more "finished" packaging (and wider distribution).
Test packs are seen sporadically and remain highly (and rightly) prized. Test wrappers are found with a little more regularity but an actual test box is a rare bird and, given the lack of any identifying markings in most cases, not something that would suggest to anyone it was worth keeping. Here then, is one for the 1975 Shock Theater test: