On April 22, 2010, in Kansas City, Missouri, the Postal Service issued a 44-cent Love: Pansies in a Basket commemorative stamp.
The stamp, designed by Derry Noyes of Washington, DC, features the image of a white woven cart filled with purple pansies and green foliage. The floral design is a detail from a watercolor created by the late Dorothy Maienschein, Hallmark Cards, Inc. Introduced as a Mother's Day card in 1939, Hallmark reissued the design as a friendship card in 1941. Since Hallmark began tracking sales in 1942 to the issuance of this stamp, almost 30 million cards with this pansy cart design have been purchased, more than any card in history. The word 'LOVE' adorns the left side of the stamp.
Avery Dennison printed 300 million stamps using the gravure process. The stamps were issued in a pressure-sensitive sheet of twenty stamps.
Reference: Postal Bulletin (March 11, 2010)