Topps had jumped into inserts in 1992 and was increasing their numbers by 1993. In 1992 Topps issued the gold versions of each basecard. Each card had the name and team stamped in gold. Pretty interesting cards at the time. Foil stamping was slowly becoming the standard.
In 1993 Topps issued "Black Gold" inserts along with the regular gold which were 1 per pack, 2-3 per cello and rack pack. Black Golds were inserted at 1 per box or less. There were 44 cards total, 11 in each series of A, B, C, and D and if I recall correctly they were inserted at different rates based upon the series. These were issued in Baseball, Football, Hockey and Basketball.
As you can see, there was a funky diamond cut foil board type stuff to use. There is no indication of damaged cards and as far as I know the only issue was centering. Why do these qualify as tough pulls? Simple, building a set of these took case after case after case just to amass the 44 cards.
Topps threw a curveball as well. As in 1992 Topps Gold, Topps issued "Winner" cards that were good for all 11 cards of a particular series. In 1992 the gold cards were stamped with an extra "winner" insignia to differentiate the winners from the much tougher pack pulls.
Here are some 1993 Black gold winners:
I don't know the insertion rates of the winners and it was not apparent that the cards had been marked as such. If someone could confirm this for me that would be great. I couldn't imagine trying to build a set of these back in the day, the regular gold cards were tougher because of sheer number of them. Regardless the winner cards killed the value pretty quickly on these. These are nice looking cards and can be picked up cheaply for sure.