In 1972 he moved to Spain and then to Italy and began a collaboration with Argentine writer Carlos Sampayo which produced, among others, the detective series Alack Sinner (sometimes misspelled "Allack Sinner") and its spin-offs Joe's Bar and Sophie, as well as a comics biography of Billie Holiday.
The cartoonist and critic Scott McCloud, in Understanding Comics (1993), wrote that "in José Muñoz's work, dense puddles of ink and fraying linework combine to evoke a world of depravity and morbid decay".[3]