The graphic artist and painter was born and died in Mexico City. Raised in poverty, he was able to complete only elementary education before beginning work to help support his family. However, his inherent drawing talent led to attendance at the Free School of Art and Advertising in Mexico City, and subsequently in The Escuela Nacional de Artes Plásticas in 1943, where he studied engraving.

In 1944 Beltrán, a reserved and solitary man, became a member of the Taller de Gráfica Popular and remained active in the organization until 1959. His strong belief in progressive social engagement and a selfless attitude toward wealth persisted throughout his life and career. Beltrán regularly donated his work to worthy causes. In due course, he became one of the most prolific and successful Mexican graphic artists of the twentieth century, producing engravings and political cartoons for several leading newspapers and magazines, founding and co-founding several progressive publications, and actively promoting literacy and education. Much of his public commissions were executed in Veracruz, a region for which he had a particular affinity.

Much of Beltrán’s work in woodcuts, linoleum cuts and lithography has been lost in large part due to the artist's indifference to materialism. The largest extant body of his work was donated by Beltrán to the National Autonomous University of Mexico. Other significant holdings include the archive of the Taller de Gráfica Popular and several other universities.