Jean-Michel Basquiat was born in Brooklyn, New York, on December 22, 1960, shortly after the death of his elder brother, Max. He was the second of four children of Matilde Andrades (July 28, 1934 - November 17, 2008) and Gerard Basquiat (1930 - July 7, 2013). He had two younger sisters: Lisane, born in 1964, and Jeanine, born in 1967. His father, Gerard Basquiat, was born in Port-au-Prince, Haiti, and his mother, Matilde Basquiat, who was of Puerto Rican descent, was born in Brooklyn, New York.

"Basquiat's canon revolves around single heroic figures: athletes, prophets, warriors, cops, musicians, kings and the artist himself. In these images the head is often a central focus, topped by crowns, hats, and halos. In this way the intellect is emphasized, lifted up to notice, privileged over the body and the physicality of these figures (i.e. black men) commonly represent in the world."  Fred Hoffman hypothesizes that underlying Basquiat's sense of himself as an artist was his "innate capacity to function as something like an oracle, distilling his perceptions of the outside world down to their essence and, in turn, projecting them outward through his creative acts." Additionally, continuing his activities as a graffiti artist, Basquiat often incorporated words into his paintings. Before his career as a painter began, he produced punk-inspired postcards for sale on the street, and became known for the political-poetical graffiti under the name of SAMO. On one occasion Basquiat painted his girlfriend's dress with the words "Little Shit Brown". He would often draw on random objects and surfaces, including other people's property. The conjunction of various media is an integral element of Basquiat's art. His paintings are typically covered with text and codes of all kinds: words, letters, numerals, pictograms, logos, map symbols, diagrams and more.  A middle period from late 1982 to 1985 featured multi-panel paintings and individual canvases with exposed stretcher bars, the surface dense with writing, collage and imagery. The years 1984-85 were also the main period of the Basquiat-Warhol collaborations, even if, in general, they were not very well received by the critics.  A major reference source used by Basquiat throughout his career was the book Gray's Anatomy, which his mother had given him while he was in the hospital at age seven. It remained influential in his depictions of internal human anatomy, and in its mixture of image and text. Other major sources were Henry Dreyfuss' Symbol Sourcebook, Leonardo da Vinci's notebooks, and Brentjes' African Rock Art.  Basquiat doodled often and some of his later pieces exhibited this; they were often colored pencil on paper with a loose, spontaneous, and dirty style much like his paintings. His work across all mediums displays a childlike fascination with the process of creating.Answer this question using a quote from the following article:

When did he start selling the postcards?