Valentine's Day reached the height of its popularity in the Victorian Era. Early Victorian valentines were lovingly made by hand from honeycombed tissue, watercolors, paper puffs, colored inks, embossed paper hearts and fine lace. Mass-produced valentines were introduced to the marketplace in the late 1830s, and by the middle of the 19th century, printing advances made card design a highly competitive market. Stand-up cards with a base and several three-dimensional fold-out layers caught on from about 1895 until 1915, as did honeycomb paper puffs that opened to form bells, fans, balls, hearts and other shapes. Samples of these and other treasured paper ephemera are on display at Henry B. Plant Museum in Hearts and Flowers: Victorian Valentines. Through Feb. 28, 10 a.m.-4 p.m. Tue.-Sat., noon-4 p.m. Sun., 401 W. Kennedy Blvd., Tampa, $5 adults/$2 children under 12, 813-254-1891, plantmuseum.com.