From Barnes & Noble.com:
At the age of 18, Corita Kent (1918-1986) entered the Roman Catholic order of Sisters of the Immaculate Heart of Mary in Los Angeles, where she taught art and eventually ran the art department. After more than 30 years, at the end of the 1960s, she left the order to devote herself to making her own work. Over a thirty-five-year career she made watercolors, posters, books and banners--and most of all serigraphs--in an accessible and dynamic style that appropriated techniques from advertising, consumerism and graffiti. The earliest of it, which she began showing in 1951, borrowed phrases and depicted images from the bible; by the 1960s, she was using song lyrics and publicity slogans as raw material.
Here is another of her other works:
Now a book will be published March 28, 2007 called Come Alive: The Spirited Art of Sister Corita