Once installed in the USA, in 1991 he begins painting the same day that Rufino Tamayo died. For Mesa, painting plays a central role in his life: it helps him to feel better, to express what he feels without words. He says that he paints “Mother nature’s marvels”, although this is not the first impression a viewer may have when looking in amazement at those terrifying figures with disturbing faces, evil smiles and unusual behaviors.