Salas' work focuses on portraiture, documentary photography and literary subjects. He has published the photobooks Apuntes para un inventario (Notes for an Inventory) on Carmen Martín Gaite; La tercera ciudad (The Third City) by Álvaro Pombo; Los días y las cosas (Days and Things) by Luis Mateo Díez; Rostros y decires (Faces and Sayings) by the poet Rafael Cadenas (all three recently awarded the Cervantes Prize); and Infinitamente Serio (Infinitely Serious) by Enrique Vila Matas. He is a regular contributor to the Cultura/s supplement of La Vanguardia. His portrait gallery includes writers such as Javier Marías, Rosa Montero, Fernando Aramburu, Javier Cercas, Paul Auster and Han Kang, among others.