It Took Decades To Create This Chess Puzzle Database (30 Thousand), 2020. https://www.youtube.com/watch?v=Y9craX0M_2A.
A chess School named after Genrikh Kasparyan (alternately Henrik Kasparian) houses his card index of chess puzzles with over 30,000 cards.
The cards are stored in stacked wooden trays in a two door cabinet with 4 shelves.
There are at least 23 small wooden trays of cards pictured in the video, though there are possibly many more. (Possibly as many as about 35 based on the layout of the cabinet and those easily visible.)
Kasparyan's son Sergei donated the card index to the chess school.
Each index card in the collection, filed in portrait orientation, begins with the name of the puzzle composer, lists its first publication, has a chess board diagram with the pieces arranges, and beneath that the solution of the puzzle. The cards are arranged alphabetically by the name of the puzzle composer.
The individual puzzle diagrams appear to have been done with a stamp of the board done in light blue ink with darker blue (or purple?) and red inked stamped pieces arranged on top of it.
ᔥu/ManuelRodriguez331 in r/Zettelkasten - Chess players are memorizing games with index cards
