Sometime in the 1970s, Andy Warhol began making "time capsules", brown cardboard boxes into which he would drop all kinds of objects from his daily life: letters, clippings from magazines and newspapers, gifts, photographs, business records, and his own and other artists' work. By the time of his death in 1987, Warhol had filled over 600 boxes that were all moved to the Warhol Museum in Pittsburgh in 1994. The Museum has been systematically opening the Time Capsules, and this Web exhibition of Time Capsule 21 allows users to tour selected contents. Dating from the 1950s to the 1970s, this particular capsule contains a great deal of Warhol's work, and the online exhibition allows linking to contextual material. For example, the caption to a Polaroid portrait of YoYo Bischofberger, the wife of a Swiss art dealer, explains how Warhol used Polaroids as part of his portrait-making process, and links to a collage of Warhol portraits, a portrait of Debbie Harry, and a video of Warhol taking photographs of Harry in preparation for making her portrait. There is also a 7-page inventory of the complete contents of Time Capsule 21.