Early Valentine’s were handmade with lace and paper, and were invented in 1834. The 1835 to 1860 period is known as the Golden Age of lacy cards. Embossed lithographs and wood cut examples were developed between 1825 and 1840 with early examples being hand colored.
Mass production pieces consisting of machine made cards featuring chromolithography began after 1840. Previously, collectors focused on cards made before 1930. When the 1980’s rolled around, interest shifted to include cards made between 1920 and 1960. Comic sheets, Art Deco, and modern images are part of the reason.
Collectors also look for a particular subject. It could be flowers, birds, animals, hearts, or even people.
There are many styles of valentines: dimensional (the background is included in the count), mechanical-flat, mechanical, novelty, flat, folded flat, hold-to-light, and greeting.
Retail value seems to be increasing steadily—especially for older examples.
There are a couple of fantastic valentine examples in my Etsy shop, which can be seen here.
What kinds of Valentine's do you have in your collection?