The Nancy and Henry Rosin Collection of Valentine, Friendship, and Devotional Ephemera has been donated to the Huntington Library in San Marino, California.
Over the course of several decades, the Rosins accumulated over 12,000 cards and love notes.
The collection includes 19th and 20th century European pop-up cards
All date to 1684-1970 and were produced in Europe and North America.
David Mihaly, of the Huntington, said: "It is without a doubt the best in private hands in terms of quality and range within its focus—to say nothing of the sheer wonder and delight the items provide.
“Pull a string and an ingenious cobweb device lifts to reveal a mouse in a trap; unfold a die-cut valentine and watch a majestic carriage spring to life in 3-D...
“We certainly will enjoy researching and processing this collection—and hope to plan an exhibition in coming years."
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