A self-taught artist, Manolo Millares painted in a figurative style until becoming influenced by Joan Miró, Paul Klee and J. Torres-García in the late 1940s. He was particularly interested in primitive art and especially that of the Guanche people. In 1950 he founded the Los Arqueros del Arte Contemporáneo (LADAC) group. Millares moved to Madrid in 1955 and two years later along with Antonio Saura brought together a series of artists to form El Paso, the most important of the Informalist groups in Spain and active until 1960. The quest for new materials led him to employ sackcloth, which he tore, glued, sewed, knotted and painted in white, black or red, and which would become a constant feature of his work.
Numerous retrospectives in his honour have been staged in European museums: Musée de la Ville de Paris (1971), Museo Español de Arte Contemporáneo, Madrid (1975), Museo Nacional Centro de Arte Reina Sofía, Madrid (1992), Kunsthalle Bielefeld, Germany (1992), Centro Atlántico de Arte Moderno, Las Palmas de Gran Canaria (1992), Museo de Arte Abstracto Español, Cuenca, Museu d’Art Espanyol Contemporani, Palma (1997) and Fundación Antonio Pérez, Cuenca (2000). His work is present in such collections as those of the Museo de Arte Moderno in Buenos Aires, the Israel Museum (Jerusalem), the Tate Collection (London), the Museo Nacional Centro de Arte Reina Sofía (Madrid), Centro Atlántico de Arte Moderno de Las Palmas de Gran Canaria and the Artium (Vitoria-Gasteiz), among others.