Multiform (1948) belongs to a group of paintings by Mark Rothko, which signifies the transition toward his mature abstract style. These paintings, collectively known as 'Multiforms', were painted between 1947 and 1949. The artist did not officially use the name 'Multiforms'; the term was adopted by art critics and historians to describe the group of paintings. In the specific case of Multiform, it seems the title was only used after Rothko's death in 1970. It first appeared in the catalog for the Rothko exhibition held at the 1970 Venice Biennale. The catalog was put together by the staff of the Marlborough Gallery, who adopted the term 'Multiforms', claiming it was casually used by Rothko to describe this group of artworks.

Paintings such as Multiform demonstrate a transitional phase in Rothko's artistic development: the artist moved on from Surrealist imagery that inspired paintings like Rites of Lilith (1945) and Tentacles of Memory (1946). At the same time, the abstract style of Multiform foresees later color field paintings such as Untitled (Purple, White, and Red) (1953).

The term color field painting originally described a tendency in the works of Abstract Expressionist painters in the 1950s, mainly Mark Rothko, Barnett Newman, and Clyfford Still. Like the term suggests, the style's features were large flat planes of solid colors. In Multiform, the artist created a composite of colorful free form shapes, which blur together on the canvas. Rothko combined bright tones of blue, turquoise, and orange, with darker red browns. Some of these colors stand out because of their hue and brightness, while others fade into the background. However, the multitude of colors and shapes makes it hard to sufficiently distinguish between the figures and background. Around the edges of the canvas, there are three large rectangular blocks of muted colors. These rectangular surfaces would become the dominant motif of later compositions like the abovementioned Untitled (Purple, White and Red). Even though Rothko's Multiform lacks the sophistication and succinctness of later color field paintings, it is an example of the artist's complete withdrawal from figurative painting. He came to believe that the painted figure could not adequately express the world's essential and universal qualities. In Multiform, he experimented with fluid forms to create gestures that humans could not make. Ultimately, Rothko found these forms unsatisfactory, but they helped the artist to embrace abstraction.

Around the time he created Multiform, Rothko worked on other important projects. In 1948, he and his colleagues William Baziotes, David Hare, and Robert Motherwell, co-founded the New York school The Subject of the Artists. The unique curriculum gave the students the opportunity to associate with working artists and use their guidance to develop different artistic processes. Although the school was short-lived, it served as an essential hub of activity in contemporary art. In addition to teaching, Rothko also made theoretical contributions by writing texts for art magazines Tiger's Eye and Possibilities. The combination of activities that occupied Rothko during his Multiforms phase shows this was a formative period in which he developed his artistic style and philosophy.