On July 28 — National Dance Day — the U.S. Postal Service honors "four influential choreographers who changed the art of dance." Look for Isadora Duncan, José Limón, Katherine Dunham and Bob Fosse (each on their on stamp) in your mailbox this year. "Designed to look like posters advertising a performance, the stamp art captures the luminosity and mystery of a live dance performance," according to USPS.

The artwork is by James McMullan, the image and poster designer for Lincoln Center Theater productions.

Here's how the "Innovative Choreographers" commemorative stamps' subjects are characterized by the postal service:

Bob Fosse, "celebrated for directing and choreographing musicals on both stage and screen, is shown on the set of [the film] 'Sweet Charity' (1969). Fosse received one Oscar, three Emmys, and nine Tony Awards during his career. Yet perhaps his greatest contribution was in making dance accessible to millions."

The stamp design for Isadora Duncan "reflects her interest in classical Greek dance forms and shows the seemingly effortless style that she developed. Radical for its time, her linking of movement and expressiveness garnered her worldwide critical acclaim." José Limón "is shown in a performance pose. He frequently drew inspiration from history, literature, and religion, and used natural movement and gesture in his choreography. His virile, powerful works elevated the importance of the male dancer in modern dance. Many of Limón's works are considered classics and continue to be performed today."

"Founder of one of the first African-American dance companies in the United States," Katherine Dunham was "the first choreographer to develop a formal dance technique that combined Caribbean and African dance elements with aspects of ballet. She is shown in a pose from her critically acclaimed ballet L'Ag'Ya."

Fosse's work lives on in the current Broadway production of Chicago.

The "Innovative Choreographers" stamps are Forever stamps (meaning they can be used in the future even if postage rates increase). They will be dedicated at a first-day-of-issue ceremony on July 28 in downtown Los Angeles, CA, at the Grand Park.

National Dance Day was created by Nigel Lythgoe, executive producer and judge for the "So You Think You Can Dance" television series. He will dedicate the stamp at its first-day-of-issue ceremony.

In 2010, Washington, DC, Congresswoman Eleanor Holmes Norton, a long-time proponent of healthy lifestyles, introduced a National Dance Day resolution to promote dance education and physical fitness across the U.S.

The stamps will go on sale nationwide at all Post Office locations after the 10 AM (PT) ceremony and will be available in panes of 20.