A portfolio is a curated selection of artwork intended to show the breadth of an artist’s work. An artist might make a portfolio for several reasons. A common type of portfolio features a selection of work that exhibits an artist’s range of styles and may be created to show dealers, curators, or other decision makers. Other times, a portfolio revolving around a single theme or medium might be sold as a single unit. This could include works by a single artist or multiple artists. A portfolio of work by a group of artists might be commissioned to support a social or political cause, such as the Artists for Obama portfolio, which included fourteen works by artists like Jasper Johns, Ann Hamilton, John Baldessari, and Julie Mehretu. Produced in a limited edition, this group of prints was sold to support the 2008 Obama presidential campaign. A single artist might create a portfolio, usually comprising a selection of prints or photographs, in order to explore a subject matter or experiment with a medium in depth. A portfolio differs from a series because the former is typically sold together, while the latter may be linked thematically, they may be separated and sold as individual pieces. Often, the objects in a portfolio work in congress to lend greater clarity to the subject matter. Artists whose bodies of work feature print portfolios include Alex Katz, Mark Dion, Max Beckmann, and Huma Bhabha.