Mengual began work as a draftsman for Rieusset, SA, in Barcelona, where he learned the technical aspects of the graphic arts, while continuing his studies in drawing, lithography, engraving and photography.
In 1948, he moved to Madrid, to continue his studies. In 1950, he returned to Barceona and set up his own studio. His work in posters, calendars, illustrations and trademarks were featured in numerous national and foreign exhibitions in Europe and North America.
In 1971, he designed his first and only commercial typeface, Vellve, for Barcelona's Neufville Type Foundry.