Paper valentines spanning three centuries of optimism about romance have been delivered to the Huntington Library, Art Collections and Botanical Gardens in San Marino, Calif.

The collection of about 12,000 cards was assembled over four decades by Nancy Rosin, a historian and collector in Franklin Lakes, N.J., whose family has donated it to the museum.

Their motifs, aside from the expected hearts and Cupids, can seem unsentimental. Images of battlefield tents represented spaces where soldiers could carve out time to write to their sweethearts, and depictions of caged mice may symbolize a desire to keep beloveds captive.

“Love was expressed in so many ways,” said Rosin, who also catalogs valentines at the Metropolitan Museum of Art in New York.