Gordana Korolija offers an interpretation of perspective and its formulation. She considers the definition of painting as a section and examines its relationship to writing and its role in understanding space. The enquiry is approached through an examination of the phenomenon of transparency in Alberti's treatise on painting. The role of the intersecting surface (vellum) is placed under scrutiny, with an emphasis on its educaative role and its implicaations for architecture. Gordana Korolija studied architecture in Belgrade and at the AA. A former AA tutor, she is Senior Research Fellow, Central Saint Martins College of Art and Design, University of the Arts London. NB: Some projected slides are unclear.