Vallen attended the prestigious Otis Parsons Art Institute where he was influenced by the great African American social realist, Charles White. Vallen considers himself, though, to be largely self-taught. Vallen has a firm commitment to figurative realism. His influences range from Goya and Daumier, to the German Expressionists and the Mexican Muralists.

In the 1970's - 80's Vallen became involved in the nascent Punk Rock scene of L.A. He produced a myriad of drawings, prints, and paintings based on those experiences. From 1979 - 1980 he worked at SLASH magazine (the West Coast's premier Punk publication) producing two cover illustrations for the infamous publication. He has created illustrations for the L.A. Weekly, L.A. Reader, California Magazine, The Progressive, Mother Jones, and South End Press. He also played a minor role in the production of "The Decline of Western Civilization", the classic Punk Rock documentary by Director Penelope Spheeris.

Concurrent to his involvement with the L.A. Punk scene, Vallen also developed fraternal ties to the large Central American refugee community, which was then seeking asylum from the terrible wars engulfing the region. Sympathetic to their plight, Vallen was the first to create and distribute political posters on the streets of L.A. Those artworks combined text with original images, and were expressions of solidarity with a people who were largely invisible to mainstream America. Moreover, Vallen's posters were bilingual, reviving a tradition that had reached its zenith in the 60's Chicano Arts movement.

Vallen's has long been a widely exhibited and respected artist. In 2000, two of Vallen's prints were included in an exhibition of political posters at the Museum of Modern Art (MOMA) in New York City. Another print was included in the traveling exhibit and book, "Just Another Poster? Chicano Graphic Arts in California." In 2003 his Punk Portraits were a featured part of Kantor Gallery's inaugural exhibition. More Than A Witness, a solo and retrospective exhibition that encompassed 30 years of work was held in L.A. at the A Shenere Velt Gallery.

Vallen was a member of ARTINO, an L.A. group of Latino figurative painters that came together to bring a greater appreciation of Latino art, in varying styles and mediums, to the world. Vallen helped to organize "¡El Grito! Liberation of the Spirit", an ARTINO exhibition at the Lankershim Art Gallery celebrating Mexican Independence Day. Vallen maintains a weblog http://art-for-a-change.com which focuses on art theory and commentary. He is currently preparing for a major European exhibition.