BSO is the *inverse* letterpress of a piece of OSB (Oriented Strand Board) bought from the closest Brico hardware shop to the Archivio Tipogra co, Turin (Italy), where it was inked in Re ex Blue and printed in 2000 copies with a Heidelberg OHZ from 1952. Each sheet, an image of the initial board, is folded and stapled into a sixteen-page signature.
