From this came the Noise Index, later fixed as the White Mold Index. The index was not a set of motifs or a style but a system of formal interventions. Recursion is important here: the painting opens the wall; patches of colour and forms open the painting; white patches open those forms; White Mold forms open the white patches; then the indexed forms themselves are opened again — through doubling, displacement into space, smearing, overpainting, repetition, and deliberately crooked execution. In the texts of that period this was called formal invasion and disclosure. One stabilised level of form is opened by the next. The instrument, therefore, is not an individual sign but the operation of opening itself.
