Sebastià has illustrated more than seventy children's books in Spain, Italy, France, UK, Portugal, Taiwan, Brazil and the United States.
Also, he has worked as graphic designer for several television shows, family theatre and many museums and cultural institutions.
He was selected three times for the Mostra degli illustratori di libri per ragazzi at Bologna Children’s Book Fair and also for the Society of Illustrators of New York, in the Original Art exhibition: The Fine Art of Children's Books Illustration.
He took part in illustration exhibitions at The Museum of American Illustration of New York, Chicago Art Institute, Northwestern University of Illinois, Itabashi Art Museum of Tokyo, Korea Society of Illustrators, International Illustrators Exchange of Prague and Frankfurt Book Fair.
He won the Mercè Llimona Prize, the Lola Anglada prize, the Serra d'Or Critics Prize, and twice Junceda Prizes by the Professional Association of Illustrators of Catalonia.