ABSTRACT
An Air Grid structure can be visualised by two means: it can be made as an electronic model in the virtual space available inside a computer and it can be made as a physical model. The Air Grid model is like Brunelleschi's device in so far as it relies on parallel surfaces facing one another across an empty space. Klein's best-known colour material is a kind of paint he invented, called International Klein Blue (IKB). Today, Klein is probably best known for his blue monochrome paintings but in fact IKB has a sister, namely International Klein Pink (IKP) and the pair of them have a metallic triplet: International Klein Gold (IKG) and all three of them feature in Klein's repertoire of monochrome painting. There are two additional colour materials in Klein's world of impersonal ontology, these being International Klein Immaterial (IKI), or Void as he sometimes referred to it and International Klein Nothingness (IKN).
