Some of the most celebrated artists of the 20th Century are rarely seen in front of the camera; or if they are, they appear in official portrait or genius-at-work shots.
But a new book sheds light on the everyday lives of creative luminaries such as Frida Kahlo and Andy Warhol.
Artists Unframed by Merry A Foresta pulls together rarely-seen snapshots of legendary artists with their guard down.
The intriguingly candid photos capture a Bohemian set of movers and shakers off-duty and at their zenith - on vacation, at parties and openings, and relaxing with children, books and friends.
Pablo Picasso is seen smiling by his young daughter Maya on a balcony in 1944, with a heartfelt penned caption noting that "he's very much in love". The famously enigmatic Warhol is captured in a cosy group shot with John Lennon and Yoko Ono, at a gallery opening in 1971. Lovers Diego Rivera and Frida Kahlo pose together in an extraordinary moment of intimacy at their home in Mexico.
The book, out this week, draws on photos that have been tucked away for years in the letters and diaries held by Smithsonian's Archive of American Art.
Take a look at some of our favourite snaps from the selection, below.
Diego Rivera and Frida Kahlo, date unknown
Diego Rivera and Frida Kahlo, Coyoacán, Mexico.
Frida's bedroom became her studio, and her bed became the place from which she held court with lovers, husbands, and, on this day, an art collector eager to meet the (at least temporarily) happy couple - who had just recently remarried.
Photograph by Chester Dale (1883–1962), Chester Dale Papers, 1897–1971
Andy Warhol and Corinne Kessler, 1949
Andy Warhol and Corinne Kessler on Fire Island beach, ca. 1949.
Corinne was a modern dancer and a close friend of Warhol's.
Photograph by Philip Pearlstein. Philip Pearlstein papers.
Pablo Picasso and his daughter, 1944
Pablo Picasso and his daughter Maya, ca.1944.
Likely made in Paris, where Picasso remained during World War II, the image captures one of the best-known artists in the world standing as a proud papa with nine-year-old Maya.
William and Ethel Baziotes Papers, 1916–92.
Gertrude Abercrombie, 1945
Gertrude Abercrombie kissing an unidentified individual in a Photomatic booth, ca. 1945.
Today photobooths have almost disappeared in deference to digital selfies, but in the early decades of the twentieth century, they could be found almost anywhere and were enjoyed by almost everyone - including Chicago-based painter Gertrude Abercrombie.
Gertrude Abercrombie papers.
Lee Krasner and Jackson Pollock, 1946
Lee Krasner and Jackson Pollock ca. 1946.
This summertime snapshot reveals an intimate and relaxed moment in Krasner and Pollock's passionate, sometimes tempestuous, often competitive, relationship - at their property overlooking Accabonac Creek in East Hampton.
Photograph by Ronald Stein (1930-2000). Jackson Pollock and Lee Krasnerpapers ca. 1905-84
Rockwell Kent, 1935
Rockwell Kent standing on his head, ca. 1935.
The American artist is captured in a light-hearted moment.
Rockwell Kent papers.
Yoko Ono, John Lennon, and Andy Warhol, 1971
Yoko Ono, John Lennon, and Andy Warhol, June 5, 1971.
There is no way of knowing what was being celebrated as John, Yoko and Andy (the posed familiarity of the photo suggests that everyone was on a first-name basis) on an early summer evening at the Leo Castelli Gallery in New York City.
Photograph by David Bourdon, David Bourdon Papers, 1953–1998.
Artists Unframed: Snapshots from the Smithsonian's Archives of American Art by Merry A. Forresta is on sale from 12 May 2015 (Princeton Architectural Press, £15.99)